The range's difference is the highest and lowest value of the data
RANGE= 250-150= 100
The mean would be the sum of all values divided by how many values
250+200+185+165+160+150+150+150+150 / 10 = 1720/10 = 172
The variance is the sum of squared deviations
*n=10
s^2 = (250-172)^2+(150-172)^2 / 10-1
which equals an esitmate of 1034.4444
take the square root and you get your final answer of 32.1628
The measure of the variation isn't typical for all celebs, since the numbers are only based on ten highest networths