1. A Math Song
Mean, median, mode
Mean, median, mode
Central tendency
Central tendency
The mean is the average of what you’ve got
The median’s the one in the middle spot
The mode is most frequent of the lot
The mean, median , mode
Mean, median, mode
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2. Using Bar Graphs to Represent Data
“There are three kinds of lies: lies, damned lies, and
statistics.”
Benjamin Disraeli
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3. Drawing an Unbiased Bar Graph:
a) Use at least 1/4 of your page of graph paper for your
graph.
b)Begin the vertical axis at 0.
c) Make sure the maximum value on the vertical axis is
slightly bigger than the maximum value of the data.
d) Draw each of your bars the same width.
e) Label the vertical and horizontal axis.
f) Give your graph a title.
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5. For an Unbiased Graph make
* the bars are of equal width
* the vertical axis begins at zero
* the maximum value on the vertical axis is slightly larger than the maximum data value
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6. Exaggerating the Differences in Data
Mr. Hiram Sayles, the president of the Whatsit Widget Company,
would like the increase in sales over the five years to appear as
large as possible. To draw a graph so that the increase in sales is
exaggerated,
DO NOT CHANGE THE SIZE OF THE GRAPH. JUST
CHANGE THE VALUES ON THE VERTICAL AXIS
*Minimum value close to the
lowest number
*Maximum value at or close
to the maximum
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8. Minimizing the difference
Ms. Ida Better, the president of the Better Widget Company,
would like the increase in sales of the Whatsit Widget
Company to look as small as possible.
DO NOT CHANGE THE SIZE OF THE GRAPH. JUST
CHANGE THE VALUES ON THE VERTICAL AXIS
* Minimum: 0
* Maximum: much larger than
the collected data
(4 or 5 times larger)
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10. To display the data accurately:
* begin the vertical axis at zero and end at a value just above the largest data value
* draw the bars of equal width
To maximize the difference in data:
* choose a vertical axis that begins just below the smallest data value and ends just above
the largest data value
* use a small vertical interval
To minimize the difference in data:
* begin the vertical axis at 0 and end it at a value much larger than the largest data value
* use a large vertical interval
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11. Assignment
Rules on Page 108
Page 110
Questions 1­3
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