Correlation Question

An investigator is interested in predicting scores for a measure of cognitive function from the number of hours of sleep a person gets on average. She obtains scores for both the number of hours of sleep and cognitive function from 5 people. Higher scores for cognitive function reflect higher levels of performance. Hours of sleep Cognitive function 0 2 10 6 4 2 8 4 8 6 ______________________________________________________________________________ 2. Write the null and research hypotheses for the relationship between sleep and cognitive functioning in regular prose-i.e. you do NOT need to use H0/H1 form.

3. The correlation coefficient for this problem is .875. Is it significant? Determine this by using the critical t-values table and alpha level = .05 for a two-tailed test.

4. Does the amount of sleep account for a significant amount of variability in scores for cognitive function? What proportion of variance in cognitive function is accounted for by sleep (i.e. what is the coefficient of determination?)