Question

Mr.Peterson recorded the points earned by each of his students' on the last test. The grades are shown below. 75, 82, 98, 78, 87, 83, 94, 71, 65, 96, 82, 85, 90, 79, 88 Which histogram represents the students' grades?

Answer 1

Frequency Polygon

Explanation:

A frequency polygon is a graphic form of a frequency distribution which is constructed by plotting the points (xi,fi) where xi is the class mark of the ith class and fi is the corresponding frequency and then connecting them by straight line segments provided the class intervals are equal .

Here in the given data the lowest value is 65 and the highest is 98.

So we can have class boundaries from 60-65, 65-70, 70- 75, 75-80, 80-85, 85-90, 90-95, 95-100

The class marks can be obtained as mid points of these classes. Then the corresponding frequency can be plotted against the mid- points.

The mid points are marked on the x - axis and frequency is plotted on the y- axis.