Read the data contained in the file wcgs$.$csv into your software. The data are from a $1964$ study of heart disease called the Western Collaborative Group Study $($WCGS$).$ Test for effect modification of the association between smoking status $($variable smoke; $1=$no$,2=$yes$)$ and systolic blood pressure $($variable sbp$)$ by behavioural pattern $($variable behpat; coded as a character variable with values A$1,$ A$2,$ B$3,$ B$4$ for the $4$ different patterns$),$ adjusting for age. Use A$1$ as the reference category for behavioural pattern. Write the regression model for an individual who smokes and has behavioural pattern A$2$ and state if there is significant effect modification.