Question

For a sample of 50 firms taken from a particular industry the mean number of employees per firm is 420.4 with a sample standard deviation of 55.7. There is a total of 380 firm in this industry.

(i) Determine the standard error of the mean to be used in conjunction with estimating the population mean by a confidence interval.

Answer 1

For a sample of 50 firms taken from a particular industry the mean number of employees per firm is 420.4 with a sample standard deviation of 55.7.

$n=50, s=55.7$

$$se=\dfrac{s}{\sqrt{n}}=\dfrac{55.7}{\sqrt{50}}\approx7.8772$$