1. Warm Up
Consumers of diet food products are concerned about the number of calories in each meal. A manufacturer advertises the number of calories in a frozen dinner is 440. A random sample of 12 dinners was found to have the following calorie count: ) Is there significant statistical evidence the mean calories in these dinners is more than 440?(a = 0.05) 2) Construct a 90% confidence interval to estimate the mean calorie count in these dinners. (You may assume the conditions for inference are met)

2. Practice
Describe the details of the error and the consequences for both a Type I and Type II error. Boston Scientific makes heart stents to treat heart attack patients. To approve a new stent design for use they will test the proportion of stents that fail. Stents currently in use fail at a rate of p = To test the new stents the null and alternate hypothesis are: Null: Ho p = 0.15 Alternate: Ha p < 0.15

3. Practice
Data from the National Retail Foundation taken in 2011 indicates that people spend an average of $55 on a graduation gift. The population standard deviation is $25. You believe (or hope?) Leland friends and families will spend more and would like to conduct a survey to determine if this is true. Your study will use n=80 and a = ) Define the null and alternate hypotheses. 2) Define a Type I error in the context of this study. 3) Determine the minimum value for the mean gift value in your study so that you will reject the null hypothesis.

4. Practice
A 2009 study found that, for customers at McDonald’s, Burger King and Wendy’s, the mean calorie consumption at a meal is 857 calories with a standard deviation of 477 calories. An executive at Subway believes her customers consume, on average, fewer calories and wants to conduct a random survey of 85 customers (use a = 0.01 and assume s for Subway customers is also 477 calories). 1) Determine the maximum value for the mean number of calories in this new study so that you will reject Ho. 2) What is the power of this study (assume the mean calorie consumption at Subway is actually 700)?