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Psychology 400-3003
Psychological Statistics
Spring 2015- Homework #3
Dr. Hitlan
Name___________________________________
Multiple Choice (1-point each)
1. A sample of n = 25 scores has a mean of M = 11. If each score in the sample is multiplied by 6, the new mean would be
_____.
a. 11
b. 6
c. 66
d. 150
2. What is the median for the following set of scores? Scores: 1, 4, 6, 7
a. 7
b. 6
c. 5
d. 4
3. A teacher gave a reading test to a class of 5th-grade students and computed the mean, median, and mode for the test
scores. Which of the following statements cannot be an accurate description of the scores?
a. The majority of the students had scores above the mean.
b. The majority of the students had scores above the median.
c. The majority of the students had scores above the mode.
d. All of the other options are false statements.
4. For a negatively skewed distribution with a mode of X = 25 and a mean of M = 20, the median is probably _____.
a. greater than 25
b. less than 20
c. between 20 and 25
d. cannot be determined from the information given
5. A researcher is measuring problem-solving times for a sample of n = 20 children. However, one of the children fails to
solve the problem so the researcher has an undetermined score. What is the best measure of central tendency for these
data?
a. the median
b. the mode
c. the mean
d. central tendency cannot be determined for these data.
6. A distribution is positively skewed. Which is the most probable order for the three measures of central tendency?
a. mean = 40, median = 50, mode = 60
b. mean = 60, median = 50, mode = 40
c. mean = 40, median = 60, mode = 50
d. mean = 50, median = 50, mode = 50
7. A researcher measures personality for a sample of n = 50 people and classifies each person as Type A, Type B, or Type
C personality. Which measure of central tendency would be appropriate to summarize these measurements?
a. mean
b. median
c. mode
8. What is the purpose for obtaining a measure of central tendency? Why is it necessary to have more than one standard
procedure for defining and measuring central tendency. (3-points)
9. For the following set of scores, identify which measure would provide the best description of central tendency and
explain your answer. (3-points)
Scores: 0, 40, 41, 43, 43, 44, 45, 47, 48.
10. What are the two characteristics of the mean that have to do with deviation scores (use words, not symbols)? (1-point
each)
1.
2.
11. Find the mean, the median, and the mode for the set of scores in the frequency distribution table below.
X
5
4
3
2
1
f
7
3
4
3
1
Mean = __________ (2-points)
Median = ________ (2-points)
Mode = __________ (1-point)
12. A sample of n = 6 scores has a mean of M = 8. If one score with a value of X = 3 is removed from the sample, what is
the mean for the remaining scores? (2-points)
13. Describe two circumstances where the median would provide a better measure of central tendency than the mean. (1point each)
1.
2.