Question

The table displays the scores of students on a recent exam. Find the mean of the scores to the nearest 10th.

Score: 65, 70, 75, 80, 85, 90
Number of students: 4, 2, 2, 1, 7, 5

Answer 1

To find the mean, we need to multiply each score by the corresponding number of students, add up all of these products, and then divide by the total number of students. We can set up a table to do this:

Score | Number of Students | Product (Score * Num. of Students)
------|-------------------|----------------------------------
65 | 4 | 260
70 | 2 | 140
75 | 2 | 150
80 | 1 | 80
85 | 7 | 595
90 | 5 | 450

To find the total product, we add up the rightmost column:

260 + 140 + 150 + 80 + 595 + 450 = 1675

To find the total number of students, we add up the middle column:

4 + 2 + 2 + 1 + 7 + 5 = 21

Finally, we divide the total product by the total number of students to get the mean:

1675 / 21 = 79.76

Rounded to the nearest tenth, the mean is 79.8.