Question

A survey of 14 middle school students showed the mean number of minutes students talked on the cell phone in a week was 133. What is the total number of minutes those students talked in a week?

Answer 1

the main formula of the mean is    
M= [x1+x2+x3+x4+ . . . +x13+x14] / 14
14 is the number of school
x1, x2, x3... are number of minutes students talked on the cell phone in a week, 
so if M= 133 we can get   x1+x2+x3+x4+ . . . +x13+x14] = 133 x 14=1862mn
the answer is 1862 min