OPTION LS=80 PS=55;
DATA lotsize1;                                        
        INPUT size hours;   
        DATALINES;          
    80  399
    30  121
    :
    :
    70  323
    ;    
RUN; 
PROC IML;
	USE lotsize1;
	READ ALL;
	Y=hours;
	c1=j(25,1,1);
	X=c1 || size;
	PRINT X Y;

	XPX=X`*X;
	XPY=X`*Y;
	b=inv(XPX)*XPY;
	PRINT XPX XPY b;
QUIT;

******************************************************************
                                 The SAS System

                                 X                   Y

                                 1        80       399
                                 1        30       121
                                 1        50       221
                                 1        90       376
                                 1        70       361
                                 1        60       224
                                 1       120       546
                                 1        80       352
                                 1       100       353
                                 1        50       157
                                 1        40       160
                                 1        70       252
                                 1        90       389
                                 1        20       113
                                 1       110       435
                                 1       100       420
                                 1        30       212
                                 1        50       268
                                 1        90       377
                                 1       110       421
                                 1        30       273
                                 1        90       468
                                 1        40       244
                                 1        80       342
                                 1        70       323


                          XPX                 XPY         b

                           25      1750      7807 62.365859
                         1750    142300    617180  3.570202