/* read the input data set */

Data new ;

  Set sashelp.shoes ;

  if product='Boot' ;

run ;

 

/* print the data */

proc print data=new ;

run ;

 

/* create a scatter plot of sales vs. inventory */

proc plot data=new ;

  plot sales*inventory ;

run ;

 

/* run a regression of sales on inventory */

/* compute the confidence interval (CLM) and prediction interval (CLI) */

/* output the residuals and predicted values to a new data set called resid1 */

proc reg data=new ;

  model sales=inventory / clm cli ;

  output out=resid1 r=res p=pred;

run ;

 

/* create a residual plot */

proc plot data=resid1 ;

  plot res*pred ;

run ;

 

/* use proc univariate to examine the residuals and create a box plot */

proc univariate data=resid1 plots ;

  var res ;

run ;

 

/* delete the outlier from the data set */

data new2 ;

  set new ;

  if inventory>700000 then delete ;

run ;

 

/* re-plot the data without the outlier */

proc plot data=new2 ;

  plot sales*inventory ;

run ;

 

/* re-run the regression analysis without the outlier */

proc reg data=new2 ;

  model sales=inventory / clm cli ;

output out=resid2 r=res p=pred;

run ;

 

/* create a new residual plot */

proc plot data=resid2 ;

  plot res*pred ;

run ;

quit ;