Try this formula:
n = [(z-value * sd)/E]^2
With your data:
n = [(1.96 * 40)/10]^2
I'll let you finish the calculation. Remember to round the answer to the nearest whole number.
How large a sample should be selected to provide a 95% confidence interval with a margin of error of 10 (to the nearest whole number)? Assume that the population standard deviation is 40.
2 answers
61.4656