The following data have to do with the relationship betweenmaternal smoking (# of cigarettes smoked per day,

which is variable X) and infant birth weight (which is variableY). (?X, ?X², ?Y, ?Y², and ?XY havealready been

calculated for you and are shown below in redfont.)

Cigarettes Per Day (X) X²    InfantBirth Weight (Y) Y² XY

2                                                        4                                            7.5                                 56.25                             15.0

6                                                      36                                            7.2                                 51.84                             43.2

10                                               100                                            6.9                                 47.61                             69.0

12                                                  144                                            6.2                                 38.44                             74.4

14                                               196    5.8 33.64 81.2

?X =44                                        ?X²=480                              ?Y=33.6                      ?Y²=227.78             ?XY= 282.8

What is the y-intercept (a) for this data?

		6.05
		6.67
		7.95
		8.33
		57.90
		5.49