/* This is an example of the REG procedure in SAS */

/* SAS code for least squares estimation of */
/* a simple linear regression model         */

/* Consider the example on pg. 15 of the book */


/* I am calling the data set "task".  */
/* The predictor variable is age.     */
/* The response variable is attempts. */

data task;
  input age attempts;
cards;
20 5
55 12
30 10
;
run;

PROC REG DATA = task;
  MODEL attempts = age;
  OUTPUT OUT=NEW P=PRED;  /* creates an output data set for plot below */
run;

/* The following code includes a plot of the data and the fitted regression line: */
/* Note this uses the data set NEW and the variable PRED created above.           */

symbol1 v=circle l=32  c = black;
symbol2 i = join v=star l=32  c = black;
PROC GPLOT DATA=NEW;
PLOT attempts*age PRED*age/ OVERLAY;
RUN;

/* Note from the output, the fitted regression equation is: */
/* Y-hat = 2.8077 + 0.1769X                                 */

/* Note MSE = 5.6538, and sqrt(MSE) = 2.378. */
/* (Can you find these in the SAS output?)   */