How to analyse double stem-leaf plot and draw double box-whisker plot

1. - Mr Kim

2. Before viewing this lesson, please view:
Finding Interquartile Range from Stem-Leaf Plot 1
Finding Interquartile Range from Stem-Leaf Plot 2

3. Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9

4. Here’s an example of
Double-Stem Leaf Plot
comparing two classes’ test
results
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9

5. We need to find the Median,
Lower and Upper Quartile,
Lowest and Highest score to
draw a Box-Whisker Plot
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9

6. To skip to drawing
Box-Whisker Plot, go to
slide number 113
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9

7. Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Let’s look at Class B first

8. Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
The Lowest score is…

9. Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
The Lowest score is 51

10. Lowest Score: 51
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9

11. Lowest Score: 51
The Highest score is…
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9

12. Lowest Score: 51
The Highest score is 89
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9

13. Lowest Score: 51
Highest Score: 89
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9

14. Lowest Score: 51
Highest Score: 89Now, let’s find the
Median
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9

15. Lowest Score: 51
Highest Score: 89Remember the directions
when crossing off
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9

16. Lowest Score: 51
Highest Score: 89
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
“In”

17. Lowest Score: 51
Highest Score: 89
“Out”
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9

18. Lowest Score: 51
Highest Score: 89
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
“In”

19. Lowest Score: 51
Highest Score: 89
“Out”
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9

20. Lowest Score: 51
Highest Score: 89
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
“In”

21. Lowest Score: 51
Highest Score: 89
“Out”
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9

22. Lowest Score: 51
Highest Score: 89
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
“In”

23. Lowest Score: 51
Highest Score: 89
“Out”
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9

24. Lowest Score: 51
Highest Score: 89
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
“In”

25. Lowest Score: 51
Highest Score: 89
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
“Out”

26. Lowest Score: 51
Highest Score: 89
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9

27. Lowest Score: 51
Highest Score: 89
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
So the Median is in
between 60 and 62
which is …

28. Lowest Score: 51
Highest Score: 89
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
So the Median is in
between 60 and 62
which is 61

29. Lowest Score: 51
Highest Score: 89
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Median: 61

30. Lowest Score: 51
Highest Score: 89
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Median: 61
Now find the Lower
Quartile

31. Lowest Score: 51
Highest Score: 89
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Median: 61
Don’t forget to divide
the sides correctly

32. Lowest Score: 51
Highest Score: 89
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Median: 61
Don’t forget to divide
the sides correctly

33. Lowest Score: 51
Highest Score: 89
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Median: 61
Find the Lower Quartile

34. Lowest Score: 51
Highest Score: 89
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Median: 61“In”

35. Lowest Score: 51
Highest Score: 89
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Median: 61“Out”

36. Lowest Score: 51
Highest Score: 89
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Median: 61“In”

37. Lowest Score: 51
Highest Score: 89
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Median: 61“Out”

38. Lowest Score: 51
Highest Score: 89
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Median: 61

39. Lowest Score: 51
Highest Score: 89
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Median: 61
So the Lower Quartile is
in between 53 and 58
which is …

40. Lowest Score: 51
Highest Score: 89
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Median: 61
So the Lower Quartile is
in between 53 and 58
which is 55.5

41. Lowest Score: 51
Highest Score: 89
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Median: 61
Lower Quartile:
55.5

42. Lowest Score: 51
Highest Score: 89
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Median: 61
Lower Quartile:
55.5
Find the Upper Quartile

43. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
“In”

44. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
“Out”

45. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
“In”

46. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
“Out”

47. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9

48. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
So the Upper Quartile is
in between 64 and 74
which is …

49. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
So the Upper Quartile is
in between 64 and 74
which is 69

50. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69

51. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Also note, Class B data is
Positively Skewed since…

52. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Also note, Class B data is
Positively Skewed since it’s
leaning towards the Left

53. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Also note, Class B data is
Positively Skewed since it’s
leaning towards the Left

54. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69

55. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Now let’s look at Class A

56. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest score is…

57. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest score is 51

58. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
You read backwards 

59. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51

60. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest score is…

61. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest score is 87

62. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87

63. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87 Now, let’s find the
Median

64. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87 Remember the directions
when crossing off

65. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
“In”

66. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
“Out”

67. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
“In”

68. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
“Out”

69. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
“In”

70. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
“Out”

71. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
“In”

72. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
“Out”

73. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
“In”

74. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
“Out”

75. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
“In”

76. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
“Out”

77. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
“In”

78. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
“Out”

79. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87

80. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
So the Median is …

81. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
So the Median is 74

82. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
Median: 74

83. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
Median: 74
Now find the Lower
Quartile

84. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
Median: 74
Don’t forget to divide
the sides correctly

85. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
Median: 74
Don’t forget to divide
the sides correctly

86. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
Median: 74
Find the Lower Quartile

87. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
Median: 74 “In”

88. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
Median: 74 “Out”

89. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
Median: 74 “In”

90. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
Median: 74 “Out”

91. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
Median: 74 “In”

92. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
Median: 74 “Out”

93. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
Median: 74

94. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
Median: 74
So the Lower Quartile
is…

95. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
Median: 74
So the Lower Quartile
is 63

96. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
Median: 74
Lower Quartile:
63

97. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
Median: 74
Lower Quartile:
63
Find the Upper Quartile

98. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
Median: 74
Lower Quartile:
63
“In”

99. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
Median: 74
Lower Quartile:
63
“Out”

100. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
Median: 74
Lower Quartile:
63
“In”

101. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
Median: 74
Lower Quartile:
63
“Out”

102. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
Median: 74
Lower Quartile:
63
“In”

103. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
Median: 74
Lower Quartile:
63
“Out”

104. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
Median: 74
Lower Quartile:
63

105. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
Median: 74
Lower Quartile:
63
So the Upper Quartile
is…

106. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
Median: 74
Lower Quartile:
63
So the Upper Quartile
is 85

107. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85

108. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
Also note, Class A data is
Negatively Skewed since…

109. Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Lowest Score: 51
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
Also note, Class A data is
Negatively Skewed since it’s
leaning towards the Right

110. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
Also note, Class A data is
Negatively Skewed since it’s
leaning towards the Right

111. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
If you find that confusing,
since most of the scores are
on the higher end, it is
Negatively Skewed

112. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85

113. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Class A Class B
2 1 5 1 2 3 8 9
3 0 6 0 2 4 4
8 6 4 4 2 0 7 4 5
7 6 6 5 3 8 9
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
Now that we have our
details, let’s draw our
Box-Whisker Plot

114. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85

115. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
Our smallest number here
is…

116. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
Our smallest number here
is 51

117. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
And our biggest number
is…

118. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
And our biggest number
is 89

119. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
So we are going to draw a
scale starting from 50

120. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
So we are going to draw a
scale starting from 50
50

121. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
50
And go up by 5s until we
reach 90

122. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
And go up by 5s until we
reach 90
50 55

123. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
And go up by 5s until we
reach 90
50 55 60

124. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
And go up by 5s until we
reach 90
50 55 60 65 70

125. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
And go up by 5s until we
reach 90
50 55 60 65 70 75 80 85 90

126. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
50 55 60 65 70 75 80 85 90

127. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
Now, let’s start with
the Right side
50 55 60 65 70 75 80 85 90

128. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
50 55 60 65 70 75 80 85 90
Put a line on 51 on
the scale above

129. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
50 55 60 65 70 75 80 85 90
Put a line on 51 on
the scale above

130. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
50 55 60 65 70 75 80 85 90
Because 51 is about
there

131. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
50 55 60 65 70 75 80 85 90
Now, put a line on
89

132. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
50 55 60 65 70 75 80 85 90
Now, put a line on
89

133. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
50 55 60 65 70 75 80 85 90
Now put a bigger
line on 55.5

134. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
50 55 60 65 70 75 80 85 90
Now put a bigger
line on 55.5

135. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
50 55 60 65 70 75 80 85 90
As well as on 61

136. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
50 55 60 65 70 75 80 85 90
As well as on 61

137. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
50 55 60 65 70 75 80 85 90
And 69

138. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
50 55 60 65 70 75 80 85 90
And 69

139. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
50 55 60 65 70 75 80 85 90
And finally, connect
the lines

140. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
50 55 60 65 70 75 80 85 90
And finally, connect
the lines

141. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
50 55 60 65 70 75 80 85 90
And finally, connect
the lines

142. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
50 55 60 65 70 75 80 85 90
And finally, connect
the lines

143. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
50 55 60 65 70 75 80 85 90
That’s one Box-Whisker
Plot complete

144. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
50 55 60 65 70 75 80 85 90
Now, let’s do the
Left side

145. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
50 55 60 65 70 75 80 85 90
Repeat the same
steps

146. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
50 55 60 65 70 75 80 85 90
But draw the lines above
the Box-Whisker Plot

147. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
50 55 60 65 70 75 80 85 90
Put a line on 51

148. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
50 55 60 65 70 75 80 85 90
Put a line on 51

149. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
50 55 60 65 70 75 80 85 90
Put a line on 87

150. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
50 55 60 65 70 75 80 85 90
Put a line on 87

151. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
50 55 60 65 70 75 80 85 90
Bigger line on 63

152. Bigger line on 63
Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
50 55 60 65 70 75 80 85 90

153. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
50 55 60 65 70 75 80 85 90
And 74

154. And 74
Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
50 55 60 65 70 75 80 85 90

155. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
50 55 60 65 70 75 80 85 90
And 85

156. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
50 55 60 65 70 75 80 85 90
And 85

157. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
50 55 60 65 70 75 80 85 90
And finally, connect
the lines

158. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
50 55 60 65 70 75 80 85 90
And finally, connect
the lines

159. Lowest Score: 51 Lowest Score: 51
Highest Score: 89
Median: 61
Lower Quartile:
55.5
Upper Quartile:
69
Highest Score: 87
Median: 74
Lower Quartile:
63
Upper Quartile:
85
50 55 60 65 70 75 80 85 90
And that’s how you draw
Double Box-Whisker Plot
from Double Stem-Leaf
Plot!