You have 5 readings and wanted to compute the standard devia

You have 5 readings and wanted to compute the standard deviation of the sample, s. Unfortunately you punched the wrong button on your calculator and find the population standard deviation. The value of sigma for this data is 3

calculate s, the sample standard deviation.

Solution

Population std deviation = 3

Sample size = 5

For populations divide the sum of the squared deviations by the population size and for samples divide the sum of the squared deviations by n-1, one less than the sample size.(here it is 4)

The reason is that, when working with samples, we estimate the mean - Mean is sum/n.

So reduce n by 1 to get correct degrees of freedom.

s = Sample std dev = 3/2 =

1.5