Question

Find the sample size required to estimate the mean age of registered drivers in the United States. Assume that we want 95% confidence that the sample mean is within 1/2 year of the true mean age of the population. Also assume that the standard deviation of the population is known to be twelve years

Answer 1

Explanation:

n = (1.96^2 * 12^2) / 0.5^2

n = 1387.84

Rounding up to the nearest whole number, we need a sample size of at least 1388 drivers to estimate the mean age of registered drivers in the United States with 95% confidence that the sample mean is within 1/2 year of the true mean age of the population.