Osteoporosis is a degenerative disease that primarily affects women over the age of 60 . A research analyst wants to forecast sales of StrongBones, a prescription drug for treating this debilitating disease. She uses the model Sales =6+1 Population +2 Incone + c. where Sales is the sales of StrongBones (in $1,000,000 s), Population is the number of women over the age of 60 (in millions), and Income is the average income of women over the age of 60 (in $1,000 s). She collects data on 39 cities across the United States and obtains the following regression results: a. What is the sample regression equation? Note: Enter your answers in millions rounded to 2 decimal places. b-1. Interpret the coefficient of population. As the number of women over the age of 60 increases by 1 million, soles of StrongBones is predicted to increase by $8.10 million. As the number of women over the age of 60 increases by 1 million, sales of StrongBones is predicted to increase by $7.32 million. As the number of women over the age of 60 increases by 1 million, sales of StrongBones is predicted to increase by $8.10 milion, hoiding income constant. As the number of women over the age of 60 increases by 1 miltion, sales of StrongBones is predicted to increase by $7.32 -2. Interpret the coefficient of income. As the average income of women over the age of 60 increases by $1,000, sales of StrongBones is predicted to increase by $8.10 million. As the average income of women over the age of 60 increases by $1,000, sales of StrongBones is predicted to increase by $7.32 million. As the average income of women over the age of 60 increases by $1,000, sales of StrongBones is predicted to increase by $8.10 million, holding population constant. As the average income of women over the age of 60 increases by $1,000, sales of StrongBones is predicted to increase by $7.32 million, holding population constant. c. Predict sales if a city has 1.4 million women over the age of 60 and their average income is $42,000. Note: Enter your answer in millions rounded to 2 decimal places