The Following Table gives the sales for the Sasquatch Men's Shoe store:

Question

Shoe Size , Frequency (number of pairs sold)
4 , 8
5 , 12
6 , 31
7 , 50
8 , 58
9 , 46
10 , 37
11 , 14
12 , 11

1)determine the mean for the distribution, correct to 2 decimal places.

2) Determine the standard deviation, correct to 2 decimal places .

for number 2 is the answer 19.37?