2.) J. McWhorter et al. of the College of Health Sciences at the University of N
ID: 2960421 • Letter: 2
Question
2.) J. McWhorter et al. of the College of Health Sciences at the University of Nevada, Las Vegas, studied physical therapy students during their graduate-school years. The researchers were interested in the fact that, although graduate physical-therapy students are taught the principles of fitness, some have difficulty finding the time to implement those principles. In the study, published as “An Evaluation of Physical Fitness Parameters for Graduate Students” (Journal of American College Health, Vol 51, No. 1, pp. 32-37), a sample of 27 female graduate physical-therapy students had a mean of 22.46 percent body fat. You may assume that percent body fat of female graduate physical-therapy students is normally distributed with a standard deviation of 4.10 percent.a.) Obtain the margin of error for a 97% confidence level.
b.) Obtain the 97% confidence interval for the mean percent body fat for all female graduate physical-therapy students.
Explanation / Answer
bGiven n=27, xbar=22.46 , s =4.1
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(a) Given a=0.03, Z(0.015)=2.17 (check standard normal table)
So the margin of error= s/sqrt(n) =4.1/sqrt(27) =0.789
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(b) SO 97% CI is
xbar +/- Z*s/sqrt(n)
--> 22.46 +/- 2.17*0.789
--> (20.748, 24.172)
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