The word mean is a synonym for average. To find the average, you add all of the data, then divide by the amount of data received.
So, we add 2+4+3+5+4+6+5+3+6+3+7+0+8+1. That totals to 57. Then, we divide by 14 because there are 14 answers. The end result is 4.07, because we round up.