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? |