A frequency distribution is a listing of the number of students who obtained each score on a test. If 31 students take a test, and the scores range from 11 to 30 then the frequency distribution might look like Table 12.2. We also show the same set of scores on a histogram or bar graph in the Figure 12.5. The horizontal (or x axis) represents the score on the test and the vertical axis (y axis) represents the number or frequency of students. Plotting a frequency distribution helps us see what scores are typical and how much variability there are in the scores. We describe more precise ways of determining typical scores and variability next.
Score on test |
Frequency |
Central tendency measures |
17 |
1 |
|
18 |
1 |
|
19 |
0 |
|
20 |
3 |
|
21 |
2 |
|
22 |
6 |
Mode |
23 |
3 |
Median |
24 |
2 |
Mean |
25 |
0 |
|
26 |
2 |
|
27 |
6 |
Mode |
28 |
2 |
|
29 |
2 |
|
30 |
1 |
|
TOTAL |
31 |
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