Answer
See below.
Work Step by Step
a) The mean of $n$ numbers is the sum of the numbers divided by $n$.
Hence the mean: $\frac{94+62+88+85+91 }{5}=84$
b) The deviation is the difference of the data item and the mean.
Hence here the deviations: $94-84=10,62-84=-22,88-84=4,85-84=1,91-84=7$
c) The sums of the deviations: 10-22+4+1+7=0$
