Refer to the North Carolina Births Case Study in Section 1.2.
(a) Create a scatter plot of weight against gestation period and compute the correlation between the two variables.
(b) Find the least-squares regression line.
(c) Give a sentence with the interpretation of the slope and the R-squared.
(d) Create the residuals plot and comment on any unusual features. Is a linear model appropriate for the relationship between gestation period and weight?