/* From website 
   http://mortgage-x.com/x/ratesweekly.asp
*/  

/*  
These are data on mortgage rates, reported weekly. 
Over a long period of time, the series appears 
nonstationary, but the period below seemed 
relatively stationary.  The assignment is to 
model the data and is thus open ended, but 
investigate at least 3 ARMA models and 
write up a report comparing them. Give a 
conclusion about which model you'd recommend 
to use for forecasting. 
*/ 
data mortgage; input date mmddyy10. rate;
format date date7.;  
cards;
12/19/2008 	5.19
12/26/2008 	5.14
1/9/2009 	5.01
1/16/2009 	4.96
1/23/2009 	5.12
1/30/2009 	5.10
2/6/2009 	5.25
2/13/2009 	5.16
2/20/2009 	5.04
2/27/2009 	5.07 
3/6/2009 	5.15
3/13/2009 	5.03
3/20/2009 	4.98
3/27/2009 	4.85
4/3/2009 	4.78
4/10/2009 	4.87
4/17/2009 	4.82
4/24/2009 	4.80
5/1/2009 	4.78
5/8/2009 	4.84
5/15/2009 	4.86
5/22/2009 	4.82
5/29/2009 	4.91
6/5/2009 	5.29
6/12/2009 	5.59
6/19/2009 	5.38
6/26/2009 	5.42
7/3/2009 	5.32
7/10/2009 	5.20
7/17/2009 	5.14
7/24/2009 	5.20
7/31/2009 	5.25
8/7/2009 	5.22
8/14/2009 	5.29
8/21/2009 	5.12
8/28/2009 	5.14
9/4/2009 	5.08
9/11/2009 	5.07
9/18/2009 	5.04
9/25/2009 	5.04
10/2/2009 	4.94
10/9/2009 	4.87
10/16/2009 	4.92
10/23/2009 	5.00
10/30/2009 	5.03
11/6/2009 	4.98
11/13/2009 	4.91
11/20/2009 	4.83
11/27/2009 	4.78
12/4/2009 	4.71
12/11/2009 	4.81
12/18/2009 	4.94
12/25/2009 	5.05
1/1/2010 	5.14
1/8/2010 	5.09
1/15/2010 	5.06
1/22/2010 	4.99
1/29/2010 	4.98
2/5/2010 	5.01
2/12/2010 	4.97
2/19/2010 	4.93
2/26/2010 	5.05
3/5/2010 	4.97
3/12/2010 	4.95
3/19/2010 	4.96
3/26/2010 	4.99
4/2/2010 	5.08
4/9/2010 	5.21
4/16/2010 	5.07
4/23/2010 	5.07
4/30/2010 	5.06
5/7/2010 	5.00
5/14/2010 	4.93
5/21/2010 	4.84
 ; 
 proc gplot; plot rate*date;  
 run;