Question

n psychology students took a standardized test. the scores are summarized in the frequency distribution table below.

scores	frequency
180 - 199	10
200 - 219	11
220 - 239	15
240 - 259
260 - 279	11
280 - 299	56

the scores are also described in the cumulative table shown below.

scores	frequency
less than 200	10
less than 220	21
less than 240	36
less than 260	53
less than 280	64
less than 300	n

what is the missing value in the frequency distribution table?
answer =

Explanation:

Step1: Recall cumulative - frequency relationship

The cumulative frequency of a class interval is the sum of the frequencies of all previous intervals and the frequency of the current interval.

Step2: Analyze cumulative - frequency table

The cumulative frequency of the "less than 240" class is 36, and the cumulative frequency of the "less than 260" class is 53.

Step3: Calculate the missing frequency

The missing frequency (for the 240 - 259 class) is the difference between the cumulative frequency of the "less than 260" class and the cumulative frequency of the "less than 240" class. So, the missing frequency $=53 - 36=17$.

Answer:

17