1. The Normal Distribution

2. The Normal Distribution
For quantities following a normal distribution:
68.2% of the observations will be within 1 standard deviation of the mean.
95.4% of the observations will be within 2 standard deviations of the mean.
99.8% of the observations will be within 3 standard deviations of the mean.

3. The Normal Distribution

4. The Normal Distribution

5. The Normal Distribution
Practice Problem 1: Suppose the monthly sales for a product is closely approximated by a normal distribution, with a mean of 200 units and a standard deviation of 40 units. How much inventory must be available at the beginning of the month to ensure that the probability of running out of the product is no more than 0.023?

6. The Normal Distribution
Practice Problem 1: Suppose the monthly sales for a product is closely approximated by a normal distribution, with a mean of 200 units and a standard deviation of 40 units. How much inventory must be available at the beginning of the month to ensure that the probability of running out of the product is no more than 0.023?
Solution:

7. The Normal Distribution
Solution:

8. Measures of Relative Standing – Standardizing an Observation –

9. Z-Score

10. Measures of Relative Standing – Standardizing an Observation –

11. Standard Normal Table

13. Sampling Distributions

14. Applications of sampling

15. Steps for Generating a Sample Mean

16. Questions to consider

17. What’s your Weekly Entertainment Spending?
What is The Average Weekly Entertainment spending level of Marketing Research Students?

18. What’s your Weekly Entertainment Spending?
Sample #1
1, 4, 15, 17, 31
Average = 52.59
Standard Deviation = 11.25

19. What’s your Weekly Entertainment Spending?
Sample #2
2, 5, 11, 13, 37
Average = 43.72
Standard Deviation = 11.47

20. What’s your Weekly Entertainment Spending?
Sample #3
1, 8, 19, 22, 27
Average = 52.40
Standard Deviation = 9.88

21. What’s your Average Weekly Entertainment Spending?
Total Population:
Average = 49.75
Standard Deviation = 11.9
Weekly Entertainment Spending
75.0
70.0
65.0
60.0
55.0
50.0
45.0
40.0
35.0
30.0 12 10 8 6 4 2
Std. Dev = 11.90
Mean = 49.8
N = 38.00

22. Sampling Distributions

24. Central Limit Theorem

25. Confidence Interval

26. Confidence Interval Weekly Entertainment Spending Interval Estimates
75.0
70.0
65.0
60.0
55.0
50.0
45.0
40.0
35.0
30.0 12 10 8 6 4 2
Std. Dev = 11.90
Mean = 49.8
N = 38.00

27. The 95% CI

28. The 95% CI

29. The 95% CI

30. The 100(1 - )% Confidence Interval

31. Standard Normal Table

32. The 100(1 - )% Confidence Interval

33. Confidence Interval

34. Necessary Sample Size

35. Necessary Sample Size

36. Confidence Intervals for Proportions

37. Confidence Intervals for Proportions
Proportion of success
Proportion of failures

38. Confidence Intervals for Proportions

39. Necessary Sample Size

40. Necessary Sample Size