MA145 Final Exam - Takehome Portion
For each of the problems below, use the MA145 technology guide to perform a statistical analysis.
You should justify your choice of method, including any assumptions made in the use of the method.
You should indicate whether a two-tailed, left-tailed, or right-tailed analysis is appropriate,
and, in hypothesis testing problems, state the null and alternative hypotheses.
If the problem does not specify a level of significance, you should choose one.
Problem 1
The DSM-IV Axis-V Global Assessment of Functioning Scale (GAF) is a widely used, global measure of psychological, social, and occupational functioning (American Psychiatric Association, 1994). In a longitudinal study, the mean GAF score for 156 subjects in the first year was 41.2. 143 third-year subjects had a mean GAF score of 54.5. Published results of a large study suggest that a reliable value for the standard deviation on the GAF is 12.3. Can we conclude that mean GAF scores are different for first and third year subjects?
Problem 2
In an experiment to demonstrate the Stroop effect, 35 non-readers averaged 17.3 responses in 45 seconds with a standard deviation of 6.1, while 47 readers average 9.5 responses with a standard deviation of 5.7. Does this data support the claim that readers make significantly fewer responses than non-readers?
Problem 3
In a double-blind study of Major Depressive Disorder (MDD), 43 subjects are treated with seratonin-reuptake inhibitors (SRIs) while 32 are given a placebo. After 8 weeks of treatment, 16 subjects
in the SRI group have experienced a remission of MDD, while 6 subjects in the placebo group have.
Can we conclude that patients receiving the drug are more likely to remit than those receiving
a placebo?