2. Practice Page 116 -- # 21

3. Practice X = Stanford-Binet Y = WAIS b =.80 (15 / 16) =.75 a = 100 – (.75)100 = 25 Y = 25 + (.75)X 73.75 = 25 + (.75)65 It’s a bad idea to use the same cut off score for these two tests

6. What is the probability of picking an ace?

7. Probability =

8. What is the probability of picking an ace? 4 / 52 =.077 or 7.7 chances in 100

9. Every card has the same probability of being picked

10. What is the probability of getting a 10, J, Q, or K?

11. (.077) + (.077) + (.077) + (.077) =.308 16 / 52 =.308

12. What is the probability of getting a 2 and then after replacing the card getting a 3 ?

13. (.077) * (.077) =.0059

14. What is the probability that the two cards you draw will be a black jack?

15. 10 Card = (.077) + (.077) + (.077) + (.077) =.308 Ace after one card is removed = 4/51 =.078 (.308)*(.078) =.024

16. Practice What is the probability of rolling a “1” using a six sided dice? What is the probability of rolling either a “1” or a “2” with a six sided dice? What is the probability of rolling two “1’s” using two six sided dice?

17. Practice What is the probability of rolling a “1” using a six sided dice? 1 / 6 =.166 What is the probability of rolling either a “1” or a “2” with a six sided dice? What is the probability of rolling two “1’s” using two six sided dice?

18. Practice What is the probability of rolling a “1” using a six sided dice? 1 / 6 =.166 What is the probability of rolling either a “1” or a “2” with a six sided dice? (.166) + (.166) =.332 What is the probability of rolling two “1’s” using two six sided dice?

19. Practice What is the probability of rolling a “1” using a six sided dice? 1 / 6 =.166 What is the probability of rolling either a “1” or a “2” with a six sided dice? (.166) + (.166) =.332 What is the probability of rolling two “1’s” using two six sided dice? (.166)(.166) =.028

20. Practice Page 122 –#6.1 –#6.2 –#6.4

21. Practice Page 122 –#6.1 = 7 cards between 3 and jack (7)(.077) =.539 –#6.2 = (.077)(52) = 4 –#6.4 = (.077)(2) =.154 chance of getting a 5 or 6 = (78)(.154) = 12

22. Next step Is it possible to apply probabilities to a normal distribution?

23. Theoretical Normal Curve -3  -2  -1   1  2  3 

24. Theoretical Normal Curve -3  -2  -1   1  2  3  Z-scores-3-2-10123

25. We can use the theoretical normal distribution to determine the probability of an event. For example, do you know the probability of getting a Z score of 0 or less? -3  -2  -1   1  2  3  Z-scores-3-2-10123.50

26. We can use the theoretical normal distribution to determine the probability of an event. For example, you know the probability of getting a Z score of 0 or less. -3  -2  -1   1  2  3  Z-scores-3-2-10123.50

27. With the theoretical normal distribution we know the probabilities associated with every z score! The probability of getting a score between a 0 and a 1 is -3  -2  -1   1  2  3  Z-scores-3-2-10123.3413.1587

28. What is the probability of getting a score of 1 or higher? -3  -2  -1   1  2  3  Z-scores-3-2-10123.3413.1587

29. These values are given in Table C on page 384 -3  -2  -1   1  2  3  Z-scores-3-2-10123.3413.1587

30. To use this table look for the Z score in column A Column B is the area between that score and the mean -3  -2  -1   1  2  3  Z-scores-3-2-10123.3413.1587 Column B

31. To use this table look for the Z score in column A Column C is the area beyond the Z score -3  -2  -1   1  2  3  Z-scores-3-2-10123.3413.1587 Column C

32. The curve is symmetrical -- so the answer for a positive Z score is the same for a negative Z score -3  -2  -1   1  2  3  Z-scores-3-2-10123.3413.1587 Column C Column B

33. Practice What proportion of the normal distribution is found in the following areas (hint: draw out the answer)? Between mean and z =.56? Beyond z = 2.25? Between the mean and z = -1.45

34. Practice What proportion of the normal distribution is found in the following areas (hint: draw out the answer)? Between mean and z =.56?.2123 Beyond z = 2.25? Between the mean and z = -1.45

35. Practice What proportion of the normal distribution is found in the following areas (hint: draw out the answer)? Between mean and z =.56?.2123 Beyond z = 2.25?.0122 Between the mean and z = -1.45

36. Practice What proportion of the normal distribution is found in the following areas (hint: draw out the answer)? Between mean and z =.56?.2123 Beyond z = 2.25?.0122 Between the mean and z = -1.45.4265

37. Practice What proportion of this class would have received an A on the last test if I gave A’s to anyone with a z score of 1.25 or higher?.1056

38. Practice Page 128 –#6.7 –#6.8

39. Practice Page 128 –#6.7 =.0668 = test scores are normally distributed –#6.8 a =.0832 b =.2912 c =.4778

41. Note This is using a hypothetical distribution Due to chance, empirical distributions are not always identical to theoretical distributions If you sampled an infinite number of times they would be equal! The theoretical curve represents the “best estimate” of how the events would actually occurThe theoretical curve represents the “best estimate” of how the events would actually occur

42. Theoretical Distribution

43. Empirical Distribution based on 52 draws

46. Theoretical Normal Curve 

47. Empirical Distribution

50. PROGRAM http://www.jcu.edu/math/isep/Quincunx/Quin cunx.html

52. Theoretical Normal Curve 

53.  Normality frequently occurs in many situations of psychology, and other sciences