Exercise 2 Page 259

We have been given a table with the percent of Americans who have broadband connection at home.

Age	$25$	$30$	$35$	$40$	$45$	$50$
Percent	$40$	$42$	$36$	$35$	$36$	$32$

To write an equation of the regression line for the data, we first have to enter our ordered pairs into lists in our calculator. We can do this by pressing the $\boxed{\text{STAT}}$ button.

Then we choose the first option in the menu, Edit, and fill in the values in the lists $\text{L}1$ and $\text{L}2.$

Once the values have been entered, a regression can be performed by pressing the $\boxed{\text{STAT}}$ button again followed by using the right-arrow key to select the CALC menu.

This menu lists the various regressions that are available. If we choose the fourth option in the menu, LinReg(ax+b), the calculator performs a linear regression using the data that was entered.

We find the equation of the regression line by substituting the values for $a$ and $b$ into the formula. We round the values to two decimal places. To estimate the percentage of $60\text{-}$year-olds with broadband, we substitute $x=60$ into the equation and simplify. According to our linear regression of the data, about $29\%$ of all $60\text{-}$years-olds have homes with broadband.