Question: Manufacturing and Product Development Several factors determine how well a ceiling fan cools a room, including blade pitch, height from the ceiling, and revolutions per minute. Independent random samples of two types of ceiling fans were obtained, and the revolutions per minute (on high) for each was measured. The summary statistics and known variances are given in the following table
![1533_Ceiling.png](https://secure.tutorsglobe.com/CMSImages/1533_Ceiling.png)
a. Find a 99% confidence interval for the true mean difference in revolutions per minute, μ1 - μ2.
b. Using the interval in part (a), is there any evidence to suggest that the mean revolutions per minute for the Altura ceiling fan is greater than the mean revolutions per minute for the Hampton ceiling fan? Justify your answer.