Chapter 1.5, Problem 72PE

(a)

To determine

To calculate: The least squares regression line. Also, round the slope to $2$ decimal places and the $y\text{-intercept}$ to $1$ decimal place.

$\begin{array}{|cc|}\hline \begin{array}{l}\text{Number of }\\ \text{days (}x)\end{array}& \begin{array}{l}\text{Weight (lb)}\\ \text{ (}y\text{)}\end{array}\\ 0& 11.0\\ 5& 12.8\\ 12& 14.3\\ 18& 16.1\\ 24& 17.2\\ 31& 19.2\\ 40& 22.0\\ 45& 23.4\\ 52& 24.7\\ 60& 27.5\\ \hline\end{array}$

(b)

To determine

To graph: The data to find the least squares regression line of the weight of the Dodger. The data in the table gives Dodgers weight $y\text{ (in lb)}$ for $x\text{ days}$ after adoption.

$\begin{array}{|cc|}\hline \begin{array}{l}\text{Number of }\\ \text{days (}x)\end{array}& \begin{array}{l}\text{Weight (lb)}\\ \text{ (}y\text{)}\end{array}\\ 0& 11.0\\ 5& 12.8\\ 12& 14.3\\ 18& 16.1\\ 24& 17.2\\ 31& 19.2\\ 40& 22.0\\ 45& 23.4\\ 52& 24.7\\ 60& 27.5\\ \hline\end{array}$

(c)

To determine

To calculate: The time required for the Dodger to reach $90\text{\%}$ of his full-grown weight of $70\text{ lb}$ by using the model in part (a).Round to the nearest day.

(d)

To determine

To calculate: By how much does the result of part (c) of the given problem differ from the result obtained by using the model $y=0.275x+11$ .