Use the given information to find the minimum sample size required to estimate an unknown population mean µ.
-How many women must be randomly selected to estimate the mean weight of women in one age group. We want 90% confidence that the sample mean is within 2.8 lb of the population mean, and the population standard deviation is known to be 27 lb.
A) 358
B) 253
C) 252
D) 250

Question

Quizplus · Accepted Answer

To find the minimum sample size, use the formula: n = (Z*σ/E)^2, where Z is the z-score for 90% confidence (1.645), σ is the population standard deviation (27 lb), and E is the margin of error (2.8 lb). Calculating gives n ≈ 252.

Use the Given Information to Find the Minimum Sample Size