Interpreting Statistics Worksheet

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?

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?

III. Consider the correlation data given the provided data and graph:

a) How are IQ and reading achievement related?

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?

Reading Comprehension Frequency Distribution

Frequency 70 80 90 100 110 120 More 0.0 3.0 4.0 7.0 6.0 1.0 0.0

STD SCORE

Verbal IQ Frequency Distribution

Frequency 70 80 90 100 110 120 More 0.0 1.0 4.0 7.0 4.0 2.0 1.0

STD SCORE

Frequency

Rdg.Compre 90.0 99.0 101.0 115.0 97.0 98.0 92.0 104.0 103.0 117.0 100.0 98.0 96.0 105.0 78.0 121.0 82.0 85.0 81.0 82.0 88.0 97.0 110.0 121.0 98.0 95.0 89.0 109.0 100.0 100.0 96.0 101.0 105.0 105.0 80.0 99.0 75.0 89.0 78.0 86.0

Verbal IQ Score

Reading Scores