1. IUBAT–INTERNATIONAL UNIVERSITY OF BUSINESS AGRICULTURE AND TECHNOLOGY
Final examination STA 240
Full marks: 100 Time: 3 hours
ID NAME MARKS
RETURN THE QUESTION PAPER ALONG WITH THE ANSWER SCRIPT AFTER THE EXAM
1. What is statistics? Discuss its applications in your subject related area?
2. Discuss briefly about the sources of data?
3. What do you mean by frequency distribution? What is a graph?
4. Describe the advantages of graphical representation of statistical data.
5. Discuss briefly about different types of bar diagrams.
6. Prove that, AM ≥ GM ≥ HM.
7. What should be the characteristics of a good measure of central tendency?
8. Calculate AM for the following frequency distribution:
Family size (x) 2 3 4 5 8
No. of families (f) 5 10 5 6 5
9. For the following distribution, construct multiple & component bar diagrams:
Section E1 E2 I
Male 40 45 55
Female 5 10 15
10. The AM of 5 numbers is 6. If a number is 5, what is the AM of the other 4?
11. AM of 3, 5, x, 6 equals AM of 3, 9. Find the value of x.
12. Find the two numbers whose AM=10 and GM=8.
13. Find the mean and mode for the series 1, 2, 3 ……… 900.
14. Two coins are tossed; find the probability that
a) At most one tail is obtained.
b) At least one head is obtained.

2. 15. The number of persons X, in a family chosen at random has the following
distribution:
X 0 1 2 3 4
P(X) 0.1 0 m 0.2 0.3
a) Find the value of m.
b) Find the average family size E (X) and V(X).
16. Interpret the following results :
a) r = 0.79 b) r = 0.65 c) r = 0.34 d) r = 0.18
17. A die is tossed 3 times. What is the probability of
a) No fives turning up? b) 3 fives? c) 1 five?
18. Vehicles pass through a junction on a busy road at an average rate of 300 per
hour.
a. Find the probability that none passes in a given minute.
b. What is the expected number passing in two minutes?
19. Find out the following probabilities:
a) P (Z > 1.06) b) P (Z < -2.15) c) P (1.06 < Z < 4.00)
20. p(x)=x ; 0<x<1
a) Find E (X). b) Also find V(X).
21. A sample of 900 values has a mean of 3.47. Can it be reasonably regarded as a
sample from a normal population with mean 3 and standard deviation 2.7?
22. Explain stratified sampling with an example.
23. Explain systematic sampling with an example.
24. Y = 5 + 2X. Interpret α and β.
25. Find CV of two numbers 5 and 3.