A researcher wishes to estimate the mean amount of money spent per month on food by households in a certain neighborhood. She desires a margin of error of $12. Past studies suggest that a population standard deviation of $229 is reasonable. Estimate the minimum sample size needed to estimate the population mean with the stated accuracy.

Question

Quizplus · Accepted Answer

The sample size can be calculated using the formula: n = (Z*σ/E)^2, where Z is the Z-score for the desired confidence level (usually 1.96 for 95%), σ is the population standard deviation, and E is the margin of error. Plugging in the values: n = (1.96*229/12)^2 ≈ 1457.

A Researcher Wishes to Estimate the Mean Amount of Money