# Fullerton College Statistics Worksheet

**Show your work** on pages 100 – 102 of your packet (you must **do the problems exactly how you were shown in the lecture)**. SHOW A GRAPH FOR EACH PROBLEM 1 – 12!

Name

Assignment #6:

SHOW AN INDIVIDUAL GRAPH FOR EACH PROBLEM.

1. Find the percentage of cases that fall between the mean and a z score of.70.

Sketch:

Answer

2. Find the percentage of cases that fall between the mean and a z score of -.09.

Sketch:

besoro

Answer

3. Find the percentage of cases falling above a z score of 1.25.

Sketch:

Answer

4. Find the percentage of cases that fall below a z score of -.86.

Sketch:

dis

Answer

5. Find the percentage of cases that fall below a z score of 1.39.

Sketch:

Answer

6. Find the percentage of cases falling above a z score of -1.65.

Sketch:

Answer

100

7. Find the percentage of cases that fall below a z score of .13.

Sketch:

Answer

8. Find the percentage of cases that fall below a z score of -1.96.

Sketch:

Answer

9. Find the percentage of cases falling above a z score of 1.33.

Sketch:

bove

nd

tion

Answer

10. Find the percentage of cases falling above a z score of -.19.

Sketch:

under

Answer

11. Find the percentage of cases falling between a z score of -1.52 and a z of .15.

Sketch:

Non sbobo

Answer

12. Find the percentage of cases falling between a z score of -2.50 and a z of 1.65.

Sketch;

Answer

101

Lecture #7 – The Practical Applications of z-scores

13. Is “50th percentile” the same thing as “50%”? (see lecture 5 to review percentiles)

14. On a normal distribution, at what percentile must the mean fall?

15. On a normal distribution, at what percentile must the median fall?

16. On a normal distribution, at what percentile must the mode fall?

17. On a normal distribution, what percentage of scores fall below the mean?

18. On a normal distribution, what percentage of scores fall within +1 SD from the mean?

19. On a normal distribution, what percentage of scores fall within #2 SD from the mean?

20. On a normal distribution, what percentage of scores fall within +3 SD from the mean?

a

21. What are two different names for the rule referenced in the above 3 questions?

and

22. A positive z score always yields a percentile rank above

23. A negative z score always yields a percentile rank below

24. A negative z score always indicates that the raw score is below the

25. Between z scores of

under the normal curve can be found almost the entire

distribution.

26. A z score of always indicates that the raw score coincides with the mean.

The following are all FALSE. State why it is false and/or correct the statement.

27. In a normal distribution, it is sometimes possible for the mean to occur above the 50th

percentile.

28. Normal distributions may be bimodal.

29. Normal distributions are platykurtic.

a

30. The mean may be a larger value than the median in a normal distribution.

31. In a normal curve, there are more positive z scores than there are negative z scores.

32. The tails of the normal curve cross the X axis.

102