## psych stats

psych stats

X f

20-25 2

15-19 5

10-14 4

5-9 1

If the following distribution was shown in a histogram, the bar above the 15-19 interval would reach from _____ to _____

A. X = 14.5 to X = 19.5

B. X = 15.5 to X = 18.5

C. X = 15.5 to X = 19.5

D. X = 15.0 to X = 19.0

3. How many individual scores are in the distribution shown in the following graph?

A. 5

B. 6

C. 13

D. Cannot be determine

4. The distribution of the height of trees in an old forest would most likely be:

1. positively skewed

2. normal

3. negatively skewed

4. bimodal

5. The normal distribution is an example of a skewed population distribution.

True

False

6.

X f

5 2

4 4

3 1

2 3

For the following frequency distribution, N =

7. For the distribution in the following graph, what is the value of SX? Answer:

8.

X f

20-24 2

15-19 5

10-14 4

5-9 1

For the following distribution, the width of each class interval is

9. For the distribution in the following graph, how many individuals had a score of X = 2? Answer:

10. A set of scores ranges from a high of X = 96 to a low of X = 27. If these scores are placed in a grouped frequency distribution table with an interval width of 10 points, the top interval in the table would be _______.

1. 90-99

2. 90-100

3. 91-100

4. 87-96

11. The distribution of grades on a very difficult statistics exam would most likely be:

1. positively skewed

2. normal

3. negatively skewed

4. bimodal

12. X f

5 6

4 5

3 5

2 3

1 2

For the following distribution of quiz scores, if a score of X = 3 or higher is needed for a passing grade, how many individuals passed?

1. 3

2. 11

3. 16

4. 21

13. What term is used to describe the shape of a distribution in which the scores pile up on the left-hand side of the graph and taper off to the right?

1. symmetrical

2. positively skewed

3. negatively skewed

4. normal

14. In a positively skewed distribution, scores with the highest frequencies are _____.

1. on the right side of the distribution

2. on the left side of the distribution

3. in the middle of the distribution

4. represented at two distinct peaks

15. After the scores in a sample have been organized into a frequency distribution table, you can determine the number of scores (n) by simply adding the values in the f column of the table.

True

False

16. Once a set of scores has been placed in a grouped frequency distribution table, it is impossible to determine the exact values for the original scores.

True

False

17. To find SX for the scores in a frequency distribution table, you simply add the values in the X column.

True

False

18. A researcher surveys a sample of n = 200 college students and asks each person to identify his or her favorite movie from the past year. If the data were organized in a frequency distribution table, the first column would be a list of movies.

True

False

19. A group of quiz scores ranges from 3 to 10, but no student had a score of X = 5. If the scores are put in a frequency distribution table, X = 5 would not be listed in the X column.

True

False

20.In a grouped frequency distribution, a class interval listed as 10-19 has an interval width of 10 points.

True

False

21. For the set of scores in the following frequency distribution table, SX = 15.

X f

5 1

4 3

3 5

2 2

1 2

True

False