Graziano and Raulin (8th ed)Graziano & Raulin
Research Methods (8th edition)

Practice with
Manual Computations of Statistics

Listed below are several small data sets on which on can practice the manual computation of statistics. The computational procedures for these statistics range from relatively simple to exceedingly complex. We recommend that complex procedures be done with a statistical analysis computer program, such as SPSS for Windows.

  1. Compute the mean of the following numbers: 48, 39, 44, 52, 66. (answer)
  2. Compute the median for the above numbers. (answer)

  3. Compute the variance and standard deviation for the above numbers. (answer)

  4. If, instead of 66, the final score was 166, how would that change the mean and the median? (answer)

  5. Compute the mean and standard deviation for each of the two variables listed below, as well as the correlation between the two variables. Is this correlation statistically significant? (answer)

X Y
23 143
42 153
53 149
44 171
74 189
29 142
65 157
44 153
39 136
  1. Compute an independent samples t-test for the data below. Also show the mean and standard deviation. (answer)

Group 1 Group 2
11 17
16 27
25 25
23 28
26 20
19 20
18 23
22 14
  1. Compute correlated-samples t-test for the following data. Report the means, standard deviations, correlation, and t-test. (answer)

Condition 1

Condition 2

21 24
32 33
25 26
29 32
23 24
26 28
25 25
  1. Computer a one-way ANOVA for the following data in which there are three independent groups of participants. Report the descriptive statistics by group and show the ANOVA summary table. (answer)

Group 1 Group 2 Group 3
5 5 4
3 8 5
8 5 3
6 11 6
5 9 2
4 6 4
8 7 5
3 9 4
8 5 3
5 4 5