Mean scores on tests that evaluate general knowledge and vocabulary, and mean scores on tests that evaluate memory and information-processing speed are shown in Table 48 for various ages. (The higher the mean score, the better the mental function will be. The mean score for everyone in the study is 0.)

Let y be the mean score (in points) on general knowledge and
a. Construct a scatterplot that compares values of x and y.
b. Describe the four characteristics of the association. Compute and interpret r as part of your analysis.
c. Find the linear regression equation.
d. Construct a residual plot. Does it support any of the conclusions you made in part (b)? If so, which one(s)?
e. Find the coefficient of determination. What does it mean in this situation?

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Table 48 Age versus Mental Functioning Mean Memory and Information- Processing Speed Score points) 10 0.7 0.3 0.2 -0.4 Age Used to Represent Age Group Mean General Knowledge and Vocabulary Score points) -0.4 -0,3 Age Group (years)(years) 20-30 30-40 40-50 60-70 25 35 45 65 75 0.2 0.3