The distribution of the number of errors 10 students made on

The distribution of the number of errors 10 students made on a typing test is shown:

Find the mean.

Errors

Frequency

0-2

1

3-5

3

6-8

4

9-11

1

12-14

1

Solution

Errors mid point Frequency error * frequency

1 1 1

4 3 12

7 4 28

10 1 10

13 1 13

Total 10 63

Mean 6.3