Answer:
The mean is 8.4
Explanation:
First you find the class centers.
3-6 = 4.5
7-10 = 8.5
11-14 = 12.5
15-18 = 16.5
The sum of all the scores = 4.5 * 7 + 8.5 * 10 + 12.5 * 6 + 16.5 + 2 = 210
The sum of the number of scores = 7 + 10 + 6 + 2 = 25
The mean = 210/25 = 42/5 = 8.4