Variations Comparison

Question

Given the data set below, find the standard deviation and compare it with the estimate of the standard deviation using the range rule of thumb.
{36,4.15,23.4,20.25,20.25,20.25,27.25,30.05,9.75

11. The standard deviation is
(Round to the nearest tenth.)

12. Use the range rule of thumb to estimate the standard deviation
(Round to the nearest tenth.)

Answer 1

Taylor,

 

(1) The formula for the sample standard deviation is:

 

s = sqrt((∑(X_i - mean))/(n - 1)) (where x_i is each data item)

 

So, find the mean first and then use the formula

 

(2) the range rule is:

 

s ≈ (max - min)/4

 

Questions?