Access the data about head sizes versus brain weights, which are available at MyMathLab and at the Pearson Downloadable Student Resources for Math & Stats website. Treat head size as the explanatory variable and brain weight as the response variable.
a. Construct a scatterplot that describes the association between the head sizes and the brain weights for the women. Do the same for the men. Show both scatterplots in the same coordinate system if you know how to use colors or shapes to identify which points are for which gender.
b. Describe the four characteristics of the women’s association. Compute and interpret r as part of your analysis. Do the same for the men’s association.
c. How is the women’s association similar to the men’s? How is the women’s association different?
d. Print the scatterplots you constructed in part (a) and draw linear models for the women’s and men’s associations on the scatterplots. Compare the two models.
e. The author plunged his head into a kitchen sink filled with water. The excess water drained into an adjacent sink. It took 18.4 cups of water to replace the displaced water. Predict the weight of the author’s brain in pounds. Round your result to the first decimal place. There are 236.6 cm3 in 1 cup, and there is 0.002205 pound in 1 gram.
f. The data were collected for a study published in 1905. Do you have much faith in the result you found in part (e)? Explain.