Homework Pg. 481: #20: What is violated? Random condition. Not a random sample from the population, cannot make inferences about the population #26: Need to complete all sections

Unit 8: Estimating with Confidence Use a confidence interval to estimate a population mean

Verify conditions of RIN Objective(s): Verify conditions of RIN Construct and interpret a confidence interval for a population mean Determine sample size necessary for a fixed ME Emphasize the appearance of “and confidence interval” b\c there is a huge difference between the two parts of this objective. Let students know that the conditions required to use a ConfInt should be familiar.

pt.est. ± (CritVal) • (Stdev of statistic) To calculate a 95% confidence interval for µ , we use the familiar formula: pt.est. ± (CritVal) • (Stdev of statistic)

One-Samp z Int for a Pop Mean Choose an SRS of size n from a population having unknown mean µ and known standard deviation σ. As long as the conditions are met, a level C confidence interval for µ is