A medical researcher wishes to estimate the mean systolic blood pressure of heart surgery patients the day following surgery. She desires a margin of error of 2.2 mmHg. Past studies suggest that a population standard deviation of 42 mmHg is reasonable. Estimate the minimum sample size needed to estimate the population mean with the stated accuracy.

Question

Quizplus · Accepted Answer

To find the minimum sample size, use the formula for the sample size of a mean: n = (Z*σ/E)^2. Assuming a 95% confidence level, Z is approximately 1.96. Plugging in the values: n = (1.96*42/2.2)^2 ≈ 1458.

A Medical Researcher Wishes to Estimate the Mean Systolic Blood