Psychology 320: Psychological Statistics
Professor: Howard B. Lee
Lecture Notes
Week 9 : Sample Computational Problems
Professor: Howard B. Lee
Lecture Notes
Week 9 : Sample Computational Problems
Psychology 320
Sample Computational Multiple choice items.
1. Given Mx = 20, SDx = 3, My = 30, SDy = 5 and rxy = 0.5. What is the slope of
the regression line to predict X using Y?
a) 0.30 b) 0.50 c) 0.60 d) 0.83 e) 1.7
2. Given the same data in question 1, what would be correct intercept for the
regression line that predicts Y using X?
a) 11 b) 13.3 c) 13.4 d) 24 e) -4.9
3. Given the regression equation Y' = 5 + .5X, where X is a score on an
attitude scale and Y is job satisfaction score, what satisfaction score would
be predicted for an attitude score of 10?
a) 10 b) 11 c) 55 d) 56
e) not enough information to determine
4. Given N=12, SumXY = 960, SumX = 27 , SumX2 = 113, SumY = 426,
SumY2 = 16224. What is the value for r ?
a) 0 b) .01 c) .05 d) .06 e) .006
The following three questions use the following set of scores on a social
psychology exam:
87, 69, 70, 75, 78, 80, 69, 79, 88, 86, 93, 90, 56, 77, 92
5. What is the corresponding Z-score for 77?
a) 0.22 b) 0.23 c) 0.235 d) -0.23 e) -0.22
6. The raw score X = 78 has an equivalent Stanford-Binet scaled score of
a) 110 b) 111 c) 112 d) 89 e) 98
7. The percentile rank for X = 88 is
a) 76.7 b) 77 c) 78 d) 80 e) 75
8. The length of time required for an math test was found to be approximately
normal, with the average equal to 85 minutes, and a SD of 13.3 minutes.
Allowing sufficient time for 91% of the students to complete the test, the test
should be terminated after how many minutes?
a) 102.0 b) 102.8 c) 102.96 d) 103.0 e) none of these
9. A variable, X is normally distributed with unknown u but a known
standard deviation of 2.57. The number of scores in the distribution is 10000.
If 8023 scores are above the value of 12.2 what is the mean?
a) 14.38 b) 14.39 c) 10.02 d) 10.01 e) 28.42
10. For the following data, what is the sum of square residuals?
Person 1 2 3 4 5 6
X 3 8 3 2 6 7
Y 7 9 3 8 8 5
a) 2.42 b) 23.431 c) 1.976 d) 1.608 e) 15.521
A psychologist wanted to determine if the type of therapy was related to the
level (amount) of recovery for psychotic patients. The data were collected and
summarized by two graduate students. In the process, the raw data were lost
but partial observed and expected frequencies were found and given below.
Observed Frequencies
Type of Therapy Level of Recovery
High Medium Low
A 19 20 10
B ? 6 12
C 14 ? 18
Expected Frequencies
Type of Therapy Level of Recovery
High Medium Low
A 22.430 ? 13.802
B 22.887 13.028 14.085
C 19.603 11.204 12.113
11. The computed test statistic is
a) 17.89 b) 17.90 c) 17.91 d) 17.92 e) none of these
Given the following raw data collected from a psychology experiment on the
effects of a tranquilizer on depression. The lower values indicate greater
depression.
Conditions Sum
Placebo 12 8 15 13 11 13 72
Low Dose 18 20 15 21 19 93
High Dose 16 7 11 8 10 15 67
12. The sum of squares for Treatment is
a) 175.85 b) 116.03 c) 291.88 d) 87.92 e) none of these
13. Given the following scores: 1, 2, 3, 4, 5, 6, 7, 8, and 9. What is the
standard deviation of these scores?
a) 2.3 b) 2.4 c) 2.5 d) 2.6 e) 2.7
14. In a normal distribution with N = 200, we would expect to find how many
cases between +1 S.D. and + 2.0 SD?
a) 100 b) 136 c) 32 d) 27 e) 50
15. What is the probability that 5 out of 6 rats will make left turns in a
T-maze?
a) 5/32 b) 6/64 c) 7/64 d) 12/64 e) 14/64
16. Given M = 25, S.D. = 5, and N = 17. Find the value of t that tests the
hypothesis that u = 22.
a) 0.6 b) 2.0 c) 2.4 d) 2.5 e) 3.0
