MS 150 Statistics Quiz 08 Fall 2004 9.1 • Name: _______________

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.

  1. The confidence interval for the population mean male body fat is:

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

 

normal curve

Statistic or ParameterSymbolEquationsExcel
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 xbarfrom_anyz (1K) =z*sx/SQRT(n)+