Confidence Intervals for Matched Pairs
Related Topics
Mark Yourself Question
- Grab a piece of paper and try this problem yourself.
- When you're done, check the "I have answered this question" box below.
- View the solution and report whether you got it right or wrong.
Copeman is a private medical clinic. It has a total of 185 locations in B.C. and Ontario. In their efforts to rebrand the company to make it look more luxurious, all the locations were renovated last year. The executives randomly sampled 25 locations from each province and compared their respective sales revenues before and after renovations. Results:
Sample mean of the differences, $5,285
Sample standard deviation of the differences, $25,875
Sample size, n = 25
1. Is there evidence at the 1% level of significance that sales are different before and after renovations? ( here )
2. Construct a 95% confidence interval for the difference in means. What does it mean (in plain English)?