The square root of 51.84 is 7.2
1/5 = 20% so... 2/5 = 40%
40% of 7.6 is 3.04
Subtract 3.04 from 7.6, you get 4.56
The farmer sells 4.56 kilograms of pears at the Farmers Market.
The surface is the sun of all the sides. With the information provide I can only work out the volume, which is 420cm^3
When the standard deviation = 0, there is no deviation at all. So the numbers are all the same. And there are seven of them. And the average is nine.
So the sample data set would just be seven 9s.