In Exercises 5–20, assume that the two samples are independent simple random samples selected from
8. Color and Cognition Researchers from the University of British Columbia conducted a study to investigate the effects of color on cognitive tasks. Words were displayed on a computer screen with background colors of red and blue. Results from scores on a test of word recall are given below. Higher scores correspond to greater word recall.
a. Use a 0.05 significance level to test the claim that the samples are from populations with the same mean.
b. Construct a confidence interval appropriate for the hypothesis test in part (a). What is it about the confidence interval that causes us to reach the same conclusion from part (a)?
c. Does the background color appear to have an effect on word recall scores? If so, which color appears to be associated with higher word memory recall scores?
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