On a standardized spatial skills task, data reveal that in the population, people have a mean of 15 correct solutions. A psychologist tests a sample of 7 people who have brain injuries in the right cerebral hemisphere and finds that they have a Sample Mean of 13.71 and a Sum of Squares of 73. Use the one sample t-test to determine whether righthemisphere damage results in significantly reduced performance on the spatial skills task.

1. Using symbols, state the null and alternative hypotheses.

2. Assuming α = .05, what critical value should be used to test the hypothesis that people with right hemisphere damage have reduced performance on the spatial skills task?

3. Calculate the one-sample t-statistic.

4. What decision should the researcher make about the null hypothesis?

5. What conclusion should the researcher reach about the effect of right hemisphere damage on spatial skills?