Intro to statistics

Question

Suppose we want to estimate the average IQ score for the population of statistics students. What is the minimum number of statistics students that must be randomly selected for IQ tests if we want 95% confidence that the sample mean is within 2 IQ points of the population mean and the standard deviation of IQ scores is 15. Round your answer to the next whole number.

Answer 1

sample size >= (z-critical * standard deviation/margin of error)^2. z-critical for 95% confidence is 1.96. Margin of error is given as 2 and standard deviation is given as 15.