How would i solve this frequency chart?

The number of students who have a test score in the interval 71-80 is 13.

Step-by-step explanation:

Given:

The frequency chart which show the cumulative numbers of students test scores.

Now, to find the number of students who score in the interval 71-80, we will look in the frequency chart. In the chart score range of 65-80 the cumulative number of students are 13. As the 71 to 80 comes in between the score range 65-80 and there are 13 students who scored in this range.

Therefore, the number of students who have a test score in the interval 71-80 is 13.