PSY 335 Interpreting Statistics Worksheet
Testing of 20 randomly selected subjects yielded two sets of scores: Verbal IQ and Reading Comprehension. The table below displays the results and descriptive statistics, as well as frequency distribution charts for each variable and a scatterplot of the correlations between the two variables:
| Subject | Verbal IQ | Rdg. Comp. |
| 1 | 90 | 88 |
| 2 | 99 | 97 |
| 3 | 101 | 110 |
| 4 | 115 | 121 |
| 5 | 97 | 98 |
| 6 | 98 | 95 |
| 7 | 92 | 89 |
| 8 | 104 | 109 |
| 9 | 103 | 100 |
| 10 | 117 | 100 |
| 11 | 100 | 96 |
| 12 | 98 | 101 |
| 13 | 96 | 105 |
| 14 | 105 | 105 |
| 15 | 78 | 80 |
| 16 | 121 | 99 |
| 17 | 82 | 75 |
| 18 | 85 | 89 |
| 19 | 81 | 78 |
| 20 | 82 | 86 |
| MEAN | 97 | 96 |
| MEDIAN | 98 | 97 |
| MODE | 98 | 89 |
| STD.DEV. | 11.8 | 11.2 |
| RANGE | 43 | 46 |
| CORREL VERB x RDG | 0.79 |
Please answer the following questions within the appropriate column in the table below:
| I. Using the provided data and graphs, describe the frequency distribution for the IQ test:
a) What is a typical score for this sample? b) How variable are the scores? c) How are the scores distributed?
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| II. Using the provided data and graphs, describe the frequency distribution of the reading test scores:
a) What is a typical score for this sample? b) How variable are the scores? c) How are the scores distributed?
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| III. Consider the correlation data given the provided data and graph:
a) How are IQ and reading achievement related?
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| IV. Evaluate the data from a psychological testing perspective:
a) Are these samples good representations of the general population? How do you know? b) What could you do to make them a more representative sample? c) How would you interpret the correlation results? d) What are some ways this knowledge of their relationship could be used? |
