please explain these,

1) What is the primary difference between a simple linear regression and a multiple linear regression?

There is more than one dependent variable

There is more than one independent variable

The correlation coefficient is above 0.5

The coefficient of determination is above 0.5

2) The equation used to predict how tall a dog will be as an adult is =4.5 + 0.7x1+ 0.55x2, where x1is the height of the mother and x2is the height of the father. Use this equation to predict the height of a puppy whose mother is 40.3 inches tall and whose father is 45.9 inches tall.

43.10 inches

57.96 inches

53.46 inches

50.75 inches

3) The equation used to predict how long it will take to receive a package through the mail is =0.5 + 0.02x1+ 0.85x2

days, where x1is the distance to travel and x2is the weight of the package. Use this equation to predict the how long it will take to receive a package that is 85 miles away and weighs 6.7 pounds.

45.9 days

7.9 days

7.3 days

7.4 days

4) The equation used to predict how long a cold will last is =-1.8 + 0.09x1+ 3.2x2- 1.9x3, where x1

is person's temperature on the first day, x2is number of people seen each day, and x3is the amount of sleep the person gets. Use this equation to predict how long a cold will last with a temperature of 101.4 degrees, an average of 4 people seen each day, and 6 hours of sleep.

9.7 days

8.7 days

10.5 days

9.5 days