Question

For the following distribution, indicate the class boundaries (compute to the first decimal) _____, frequency _____, and cumulative frequency _____ for the interval of 56-58 _____.

Scores: 56, 51, 47, 58, 55, 52, 53, 52, 49, 55, 54, 53, 47, 51, 57, 49, 50, 50, 48, 56, 58, 47, 57, 51, 54, 57, 49, 56

Answer 1

scores in ascending order

 47 47 47 48 49 49 49 50 50 51 51 51 52 52 53 53 54 54 55 55 56 56 56 57 57 57 58 58

Class boundaries are the numbers used to separate classes. The size of the gap between classes is the difference between the upper class limit of one class and the lower class limit of the next class. In this case, gap=50−49=1

gap=1

The lower boundary of each class is calculated by subtracting half of the gap value 1/2=0.5 from the class lower limit. On the other hand, the upper boundary of each class is calculated by adding half of the gap value 1/2=0.5 to the class upper limit.

class boundaries , frequency and cumulative frequency are given in the following table:-

scores (class limit)	class boundaries	frequency	cumulative frequency
47-49	46.5-49.5	7	7
50-52	49.5-52.5	7	14
53-55	52.5-55.5	6	20
56-58	55.5-58.5	8	28