The numbers of hours worked (per week) by 400 statistics students are shown below. The cumulative percent frequency for

Question

The numbers of hours worked (per week) by 400 statistics students are shown below.  ​ The cumulative percent frequency for < 29 hours is
A) 50. 
B) 75. 
C) 200. 
D) 300.

Quizplus · Accepted Answer

To find the cumulative percent frequency for < 29 hours, we need to add up the percent frequencies for all values less than 29. From the cumulative frequency table, we can see that the percent frequency for the interval 0-9 is 3.25, for 10-19 it is 8.5, for 20-29 it is 13.5. Adding these gives:
3.25 + 8.5 + 13.5 = 25.25%
Therefore, the cumulative percent frequency for < 29 hours is 25.25%. 
The closest answer choice is B) 75 which is the complement of the cumulative percent frequency for ≥ 29 hours: 
100% - 25.25% = 74.75%, which is approximately 75%.

The Numbers of Hours Worked (Per Week) by 400 Statistics