Concept:The given data is a "more than" cumulative frequency distribution. To find the frequency (number of observations) between 250 and 300, subtract the cumulative frequency at 300 from the cumulative frequency at 250.Explanation:The table below shows the conversion from cumulative frequency to ordinary frequency:
Class Interval
Cumulative Frequency (more than)
Frequency
200–250
56
56 – 38 = 18
250–300
38
38 – 15 = 23
300–350
15
15 – 0 = 15
350–400
0
0
The number of observations between 250 and 300 is the frequency for the class 250–300, which is 38 – 15 = 23.Answer:23 (Option B)