Three hundred students took a chemistry test You sampled 50

Three hundred students took a chemistry test. You sampled 50 students to estimate the average score and the standard deviation. How many degrees of freedom were there in the estimation of the standard deviation?

Solution

The degrees of freedom for an estimate is equal to the number of values minus the number of parameters estimated en route to the estimate in question. You have 50 values in your sample, and you need to estimate one parameter, the mean, in order to find the standard deviation. 50 - 1 = 49