13. Novine knows that over the last 10 years average computer prices have fallen. She believes that average computer prices can be predicted by time, computing speed (number of instructions processed per second), memory (RAM), storage (hard drive space), and processor chip price.

a. Using Excel, develop a full linear regression model to predicted the average computer price using the variables above. Based on the model, rank the variables (using p-values) based on degrees of significance in the model.

b. Calculate the MAD for your model.

c. Observe R-squared, Significant-F, and t statistics and interpret them.

d. What is the best two variable regression model to predict average computer price? Is there a problem with using linear regression on this data?

Avg computer price	Year	Bits	RAM	Storage	Chip Price
$ 3,000.00	1990	2	4	40	870
$ 2,850.00	1991	4	8	80	800
$ 2,750.00	1992	4	8	80	790
$ 2,250.00	1993	8	16	100	700
$ 2,100.00	1994	8	24	200	500
$ 1,900.00	1995	16	32	500	450
$ 1,850.00	1996	16	64	500	400
$ 1,700.00	1997	32	64	1000	375
$ 1,500.00	1998	64	128	2000	350
$ 1,100.00	1999	64	128	4000	300