1. Because colas tend to replace healthier beverages and colas contain caffeine and phosphoric acid, researchers wanted to know whether cola consumption is associated with lower bone mineral density in women. The accompanying data lists the typical number of cans of cola consumed in a week and the femoral neck bone mineral density for a sample of 15 women.

Colas per week Bone Mineral Density (grams per cubic centimeter) 0 0.906 0 0.896 1 0.882 1 0.871 2 0.854 2 0.838 3 0.811 3 0.820 4 0.793 5 0.771 5 0.768 6 0.740 7 0.712 7 0.722 7 0.718

a) Find the least-squares regression line treating cola consumption per week as the explanatory variable.

y=_____x+____

2. The data below represent the number of days absent, x, and the final grade, y, for a sample of college students at a large university. Complete parts (a) through (e) below.

No. of absences, x	0	1	2	3	4	5	6	7	8	9
Final grade, y	88.5	85.7	82.8	80.4	77.5	73.2	63.4	68.3	65.5	62.6

(a) Find the least-squares regression line treating the number of absences, x, as the explanatory variable and the final grade, y, as the response variable.

y=_____x+_____

3. Given that x=3.6667, sx=2.0656, y=4.3333, sy=1.5108, and r=0.9378, determine the least-squares regression line.

a) y=____x+_____