Chapter 15, Problem 4E

Exercises 1 through 4 refer to the data set shown in Table 15-12 The table shows the scores on a Chem 103 test consisting of 10 questions worth 10 points each.

Table 15-12

Chem 103 test scores

Student ID	Score	Student ID	Score
1362	50	4315	70
1486	70	4719	70
1721	80	4951	60
1932	60	5321	60
2489	70	5872	100
2766	10	6433	50
2877	80	6921	50
2964	60	8317	70
3217	70	8854	100
3588	80	8964	80
3780	80	9158	60
3921	60	9347	60
4107	40

Suppose that the grading scale for the test is $\text{A}:80-100$; $\text{B}:70-79$; $\text{C}:60-69$; $\text{D}:50-59$; and $\text{F}:0-49$.

a. What percentage of the students who took the test got a grade of $D$?

b. In a pie chart showing the distribution of the test grades, what is the size of the central angle (in degrees) of the “wedge” representing the grade of $D$?

c. Draw a pie chart showing the distribution of the test grades. Give the central angles for each wedge in the pie chart.

(round your answer to the nearest degree).