Question

A sample of 15 buttons is randomly selected and the following diameters are measured in inches. Give a point estimate for the population standard deviation. Round your answer to three decimal places.

1.33,1.25,1.22,1.27,1.39,1.34,1.33,1.32,1.26,1.20,1.28,1.20,1.24,1.38,1.31

Answer 1

The point estimate for the population standard deviation is of 0.061.

Explanation:

The point estimate for the population standard deviation is the sample standard deviation.

Sample mean:

`\overline{x} = (1.33+1.25+1.22+1.27+1.39+1.34+1.33+1.32+1.26+1.20+1.28+1.20+1.24+1.38+1.31 )/(15) = 1.288`

Sample standard deviation:

Square root of the sum of the difference squared of all these values (1.33, 1.25, 1.22,...) and the mean of 1.288, divided by 15 - 1 = 14.

Using a calculator, it is of:

`s = 0.061`

The point estimate for the population standard deviation is of 0.061.