Question

The dealership plans to increase the size of the sample so that the standard deviation of the sample mean is no more than $175. Given that the true standard deviation of the price of a Civic is $825, find the sample size the dealership should use? (Hint: use the formula σ=sn)

Answer 1

22

Explanation:

Given that:

Standard deviation of sample mean (s) = 175

True standard deviation (σ) = 825

Sample size of dealership = n

s = σ/ √n

175 * √n = 825

Divide both sides by 175

√n = 825 / 175

√n = 4.71428

Square both sides

n = 22.22

n = 22 samples