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?

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?

PSY 335 Interpreting Statistics Worksheet