1. Sta220 - Statistics Mr. Smith Room 310 Class #15

2. Section 4.9

4. Copyright © 2013 Pearson Education, Inc.. All rights reserved. Definition

5. What about the shape of the sampling distribution? Two theorems provide this information.

6. Copyright © 2013 Pearson Education, Inc.. All rights reserved. Theorem

7. Copyright © 2013 Pearson Education, Inc.. All rights reserved. Theorem

8. The Central Limit Theorem is so powerful because now we no longer need to know the distribution of the population. The Central Limit Theorem applies to all types of population distributions.

9. Copyright © 2013 Pearson Education, Inc.. All rights reserved. Figure 4.39 Sampling distributions of for different populations and different sample sizes

10. Problem 4.29

11. Copyright © 2013 Pearson Education, Inc.. All rights reserved. Figure 4.40A population relative frequency distribution and the sampling distribution for

12. Copyright © 2013 Pearson Education, Inc.. All rights reserved. Figure 4.41 The sampling distribution for b.

13. Problem 4.30 A manufacturer of automobile batteries claims that the distribution of the lengths of life and its best battery has a mean of 54 months and a standard deviation of 6 months. Suppose a consumer group decides to check the claim by purchasing a sample of 50 of the batteries and subjecting them to tests that estimate the battery’s life. a)Assuming that the manufacturer’s claim is true, describe the sampling distribution of the mean lifetime of a sample of 50 batteries. b)Assuming that the manufacturer’s claim is true, what is the probability that the consumer group’s sample has a mean life of fewer 52 months?

14. Copyright © 2013 Pearson Education, Inc.. All rights reserved. Figure 4.42 The sampling distribution of in Example 6.8 for n = 50

15. Homework 4.8 and 4.9 due by Wednesday Quiz Chapter 4 and CH. 4 Homework Review due by Wednesday Test on Chapter 4 Thursday, Review will be passed out tomorrow. Chapter 5 will start Friday