A sample size n of 19 female students in MS 150 statistics spring 2005 had their body fat measured. The sample mean body fat x is 30.16 with a sample standard deviation sx of 9.54. Construct a 95% confidence interval for a population mean female body fat among females students at the national campus. Note that n ≤ 30.
Confidence interval statistics | |||
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Find a t_{c} value from a confidence level c and sample size n | t_{c} | =TINV(1-c,n-1) | |
Calculate an error tolerance E of a mean for any n ≥ 5 using sx. | E | =t_{c}*sx/SQRT(n) | |
Calculate a confidence interval for a population mean µ from a sample mean x and an error tolerance E | x-E≤ µ ≤x+E |