Find the necessary sample size.
-Weights of women in one age group are normally distributed with a standard deviation Ϭ of 14 lb. A researcher wishes to estimate the mean weight of all women in this age group. Find how large a Sample must be drawn in order to be 90 percent confident that the sample mean will not differ from The population mean by more than 3.0 lb.

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Quizplus · Accepted Answer

To find the sample size, use the formula n = (Z*σ/E)^2, where Z is the z-score for 90% confidence (1.645), σ is the standard deviation (14), and E is the margin of error (3). Calculating gives n ≈ 58.72, which rounds up to 59.

Find the Necessary Sample Size