Use R$-$software please We will use a data set that is included with the R package called mtcars, which has measures on $32$ cars from Motor Trend magazine from the $1973-74$ model years.

If you type $?$mtcars in the R console window, you will see an explanation of the data set displayed in the Help window.

You can view the first view rows of the data set by typing head$($mtcars$)$ in the console window.

We will estimate a regression model where we try to explain the miles per gallon measure $($abbreviated as mpg$)$ using the engine size of the car in cubic inches, known as displacement and abbreviated as disp. In other words, mpg will be the response variable and disp will be the explanatory variable.

Steps:

$1)$ Issue the command attach$($mtcars$)$ so that the variables in the data set are in the search path when you issue a command; this allows you to refer to the variables directly. Otherwise, you would have to write mtcars$mpg and mtcars$disp to refer to the variables.

$3)$ Use the plot$()$ function to create a scatter plot with mpg $($our response variable$)$ on the vertical axis and disp $($our explanatory variable$)$ on the horizontal axis. Remember to include your name$($s$)$ in the main title of the plot using the $$main$=$ parameter.

$5)$ Use the lm$()$ function $($which stands for linear model$)$ to estimate a regression equation with mpg as the response variable and disp as the explanatory variable. Remember to use the tilde special character $($~$)$ between the response variable and explanatory variable. The lm function returns the results as an $$object$$ that you can assign to a variable $($such as result$)$ as illustrated in the chapter $14$ R software notes.