Imagine you are estimating the difference between two population means by comparing 95% confidence intervals. If you use the 2SE rule of thumb and have desired margin of error of 5 cm, what is the approximate minimum sample size for each of the samples if the population standard deviation is 15 cm?

Question

Quizplus · Accepted Answer

The 2SE rule of thumb states that the sample size needed to achieve a desired margin of error is approximately (2 * SE)^2, where SE is the standard error of the mean. The standard error of the mean is equal to the population standard deviation divided by the square root of the sample size. So, in this case, we have:SE = 15 cm / sqrt(n)And:(2 * SE)^2 = 5 cmSolving for n, we get:n = (2 * 15 cm / 5 cm)^2 = 108Therefore, the approximate minimum sample size for each of the samples is 108.

Imagine You Are Estimating the Difference Between Two Population Means