Tucson Machinery, Inc., manufactures numerically controlled machines, which sell for an average price of $0.5 million each. Sales for these NCMs for the past two years were as follows:
Quarter Quantity (Units) Quarter Quantity (Units)
2006 2007
I 12 I 16
II 18 II 24
III 26 III 28
IV 16 IV 18
a. Hand fit a line (or do a regression using Excel).