Week 6 Live Lecture

1. B Heard Lecture for the Week 6 LabStatistics For Decision Making Not to be used, posted, etc. without my expressed permission. B Heard

3. Part 1: Normal Distributions and Birth Weights in America

4. Part 2: Central Limit Theorem and Age Distributions in the United States

5. Part 3: Finding z and t scores for Confidence Intervals

6. Part 4: Bob’s Candies (Using Confidence Intervals to decide a course of action)Week 6 Lab Not to be used, posted, etc. without my expressed permission. B Heard

7. Week 6 Lab Part 1………. Not to be used, posted, etc. without my expressed permission. B Heard

8. Birth Weights in America Week 6 Lab Not to be used, posted, etc. without my expressed permission. B Heard

9. Week 6 Lab Birth Weights in America, Number 1, part a You can see that the graph has a mean of less than 7.5, so the 37 to 39 Weeks Gestation period is the obvious choice. Not to be used, posted, etc. without my expressed permission. B Heard

10. Birth Weights in America, Number 2, part b We will identify the mean birth weight and standard deviation for the 32 to 35 week gestation period for this problem. The mean is 5.73 lbs and the standard deviation is 1.48 lb. Week 6 Lab Not to be used, posted, etc. without my expressed permission. B Heard

11. Birth Weights in America, Number 2, part b continued Using the NORMDIST function with the point in question, the mean, the standard deviation, and the cumulative value “TRUE” gives the percent of babies under 5.5 lbs. The distribution “fills” from left to right. Week 6 Lab Not to be used, posted, etc. without my expressed permission. B Heard

12. Birth Weights in America, Number 3, part b We will identify the mean birth weight and standard deviation for the over 42 weeks gestation period for this problem. The mean is 7.65 lbs and the standard deviation is 1.12 lb. Week 6 Lab Not to be used, posted, etc. without my expressed permission. B Heard

13. Birth Weights in America, Number 3, part b continued Using the NORMINV function with the .9 (left to right) to find the point at which 90% of the values are below and 10% above, the mean, and the standard deviation. The distribution “fills” from left to right. Week 6 Lab Not to be used, posted, etc. without my expressed permission. B Heard

14. Birth Weights in America, Number 4, part b We will identify the mean birth weight and standard deviation for the 37 to 39 week gestation period for this problem. The mean is 7.33 lbs and the standard deviation is 1.09 lb. Week 6 Lab Not to be used, posted, etc. without my expressed permission. B Heard

15. Birth Weights in America, Number 4, part b continued Using the NORMDIST function with the points in question, I subtracted the value for 6 from the value for 9. This was .9373 - .1112 which equals our answer .8261 Week 6 Lab Not to be used, posted, etc. without my expressed permission. B Heard

16. Birth Weights in America, Number 5, part b We will identify the mean birth weight and standard deviation for the 32 to 35 week gestation period for this problem. The mean is 5.73 lbs and the standard deviation is 1.48 lb. Week 6 Lab Not to be used, posted, etc. without my expressed permission. B Heard

17. Birth Weights in America, Number 5, part b continued Using the NORMDIST function with the point in question, the mean, the standard deviation, and the cumulative value “TRUE” gives the percent of babies under 3.3 lbs. The distribution “fills” from left to right. Week 6 Lab Not to be used, posted, etc. without my expressed permission. B Heard

18. Week 6 Lab Part 2………. Not to be used, posted, etc. without my expressed permission. B Heard

19. Age Distribution in the United States Week 6 Lab Not to be used, posted, etc. without my expressed permission. B Heard

20. Week 6 Lab Age Distribution in the United States, Number 1 The answer for number 1 is given to us. Make sure you see how it was calculated. Not to be used, posted, etc. without my expressed permission. B Heard

21. Week 6 Lab Age Distribution in the United States, Number 2 You will be finding the mean or average for the sample means in number 2. Use the Sample Means given in the lab’s Excel file. Not to be used, posted, etc. without my expressed permission. B Heard

22. Week 6 Lab Age Distribution in the United States, Number 3 Does this look like a “Bell-Shaped” curve to you? Not to be used, posted, etc. without my expressed permission. B Heard

23. Week 6 Lab Age Distribution in the United States, Number 4 On this one, use your same approach to creating a histogram that you did in a previous lab. You will use the sample data, set up your classes, find the frequencies, then create your histogram. Does it look like a normal curve????? Not to be used, posted, etc. without my expressed permission. B Heard

24. Week 6 Lab Age Distribution in the United States, Number 5 The answer for number 5 is given to us. Make sure you see how it was calculated. Not to be used, posted, etc. without my expressed permission. B Heard

25. Week 6 Lab Age Distribution in the United States, Number 6 You will be finding the standard deviation for the sample means in number 2. Use the Sample Means given in the lab’s Excel file and compare to the Central Limit Theorem in your book. What does the Central Limit Theorem say? Discuss how it applies here. Not to be used, posted, etc. without my expressed permission. B Heard

26. Week 6 Lab Part 3………. Not to be used, posted, etc. without my expressed permission. B Heard

27. Finding z and t scores, Part 3 Week 6 Lab Not to be used, posted, etc. without my expressed permission. B Heard

28. Week 6 Lab Finding z and t scores, Number 1b Just input your value under Confidence level and the z-score is calculated for you! Make sure you look at the formula. Not to be used, posted, etc. without my expressed permission. B Heard

29. Week 6 Lab Finding z and t scores, Number 2b Just input your value under Confidence level and sample size and the t-score is calculated for you! Make sure you look at the formula. Not to be used, posted, etc. without my expressed permission. B Heard

30. Week 6 Lab Part 4………. Not to be used, posted, etc. without my expressed permission. B Heard

31. Bob’s Candies (Using Confidence Intervals…), Part 4 Week 6 Lab Not to be used, posted, etc. without my expressed permission. B Heard

32. Week 6 Lab Bob’s Candies, Number 1 Use the “average” function and the “stdev” function in Excel to find the sample mean and sample standard deviation. Not to be used, posted, etc. without my expressed permission. B Heard

33. Week 6 Lab Bob’s Candies, Number 2 In answering this question, take a look at the sample size! Not to be used, posted, etc. without my expressed permission. B Heard

34. Week 6 Lab Bob’s Candies, Number 3 Based on your answer for number 2, choose the appropriate values using the same Excel functions you used in Part 3 of the lab. Not to be used, posted, etc. without my expressed permission. B Heard

35. Week 6 Lab Bob’s Candies, Number 4 For 95% you would Use the formula E=Zc*(s/sqrt n), which =1.96*(6.205/6.325)=1.923 Then find your endpoints, the Left endpoint would be x-E=Mean -1.923=______ The Right endpoint would be x+E=Mean +1.923=____ So, you can be 95% confident that the true mean amount the citizens spend per year is between ____and ______. Not to be used, posted, etc. without my expressed permission. B Heard

36. Week 6 Lab Bob’s Candies, Number 5 On this one I would take a look at say the 99% lower limit (left hand limit). Discuss this. You would do this the same way you did the previous question (Number 4). Not to be used, posted, etc. without my expressed permission. B Heard

37. Week 6 Lab Bob’s Candies, Number 6 On this question, compare Bob’s results (his data) to the national average ($75 per person). Not to be used, posted, etc. without my expressed permission. B Heard

38. Remember I will post the link to these charts at www.facebook.com/statcave Come to my facebook site throughout the week and I might post a few more hints. Week 6 Lab