A graduate student has collected data involving 66 scores. Based on these data,
ID: 3255848 • Letter: A
Question
A graduate student has collected data involving 66 scores. Based on these data, he has constructed two frequency distributions of grouped scores. These are shown here. Do you see anything wrong with these distributions? Explain>
a. Class Interval f
48-63 17
29-47 28
10-28 21
b.
Class Interval f Class Interval f
62-63 2 34-35 2
60-61 4 32-33 0
58-59 3 30-31 5
56-57 1 28-29 3
54-55 0 26-27 0
52-53 4 24-25 4
50-51 5 22-23 5
48-49 2 20-21 2
46-47 0 18-19 0
44-45 5 16-17 3
42-43 4 14-15 1
40-41 3 12-13 0
38-39 0 10-11 2
36-37 6
Explanation / Answer
The two frequency distributions does not match and they are different in respect of the class intervals. The total of the frequencies in both the distributions match but the individual class frequencies does not match. For e.g in the 1st distribution there are 17 scores in the interval 48-63 whereas in the 2nd distribution if we combine the intervals starting from 48-49 upto 62-63 and add up the frequencies then we can see that there are 21 scores in the interval 48-63. So the distributions are different. However if we plot the frequency curves for the distributions, we can see that for distribution (a) we will get a mesokurtic curve while for distribution (b) we will get a platykurtic curve.