PSY 205: Research Methods I
Module 5: Assignment
Work the following problems.
1. For each of the following data sets find the following.
(You can use the Data Analysis Toolpak (Descriptive Statistics) for most of the calculations, but you’ll need VAR and STDEV functions to calculate the unbiased estimates.)
Mean
Median
Mode
Range
Variance (for describing the data)
Standard deviation (for describing the data)
The unbiased estimate of the variance
The unbiased estimate of the standard deviation
Data Set A Data Set B Data Set C
Scores on a Math Test Scores on English Test Scores on a Test of
Spatial Ability
78 88 100
55 90 124
73 67 84
88 77 88
90 71 104
92 80 108
73 68 78
80 77 84
67 77 84
76 92 110
2. Describe the normal curve.
3. Compute the z scores for the following raw scores where X = 74 and the standard deviation = 8.
A. 66
B. 86
4. Using a distribution with a mean of 100 and a standard deviation of 15.
A. What is the percentile score of a score of 112?
B. What is the percentile score of a score of 82?
2