A sample of 27 female graduate physical therapy students had a mean of 22.46% body fat.
a. Assuming that percent body fat is normally distributed with a standard deviation of 4.10% body fat, determine a 95% confidence interval for the mean percent body fat of all female graduate physical therapy students.
Determine α = ; α/2 = ; x̄ = ; σ = ; zα/2 =
Formula for Confidence Interval:
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Show all calculations below to find the Confidence Interval
b. Obtain the margin of error, E, for the confidence interval you found in part (a).
c. Explain the meaning of E in this context in terms of the accuracy of the estimate.
d. Determine the sample size required to have a margin of error of 1.55% body fat with a 99% confidence level.