A sample size n of 22 male students in MS 150 had their body fat measured. The sample mean body fat x is 18.85 with a sample standard deviation sx of 8.63. Construct a **99%** confidence interval for a population mean male body fat.

- The confidence interval for the population mean male body fat µ is:

P( _________ ≤ µ ≤ _________ ) = 0.99 - _______ Could the population mean male body fat be above 20%, the lower limit for being overfat, at a 99% confidence level?

Statistic or Parameter | Symbol | Equations | Excel |
---|---|---|---|

Confidence interval statistics | |||

Find z from the area under the normal curve to the left of z | z | =NORMSINV(area to the left of z) | |

Calculate an x value from z, sx, n and a point estimate of µ | =z*sx/SQRT(n)+µ |