Q1) There is small but positive correlation between income and height for adults, and these data tend to follow a gently sloping line

Do this mean people who earn more money tend to be bit taller on average than people who earn less?

i) Yes, we can say this assuming that data is for random sample of adults C  

ii) No. there is no reason to believe that taller people earn more money

Q2) Following regression equation has been estimated for Y using X as independent variable

Y= 10X- 54

Now we would like to evaluate regression equation for X using Y as independent variable

i) X= 10 Y+ 54

ii) X = 0.1 Y4 54

iii) X = 0.1 Y + 5.4

iv) It is possible that none of the above is the correct equation

Q3) Store records illustrate that people who live closer to store tend to purchase more. Relationship between distance to the store in miles (X) and amount a customer spends over year in dollars (Y) fits following regression line: Y = -100 X + 1000. Interpret coefficient -100 in this regression equation.

i) For each extra mile farther from store, yearly amount spent goes down by= $100

ii) For each extra mile farther from store, yearly amount spent goes down by= $100 on average

iii) A customer who is 1 mile away from store spends $100 annually at store