The flow rate in a device used for air quality measurement depends on the pressure drop x (inches of water) across the device's filter. Suppose that for x values between 5 and 20, these two variables are related according to the simple linear regression model with true regression line y = -0.17 + 0.095x. A) What is the true average flow rate for a pressure drop of 10 in. and drop of 15 in.?
B) What is the true average change in flow rate associated with a 1 inch increase in pressure drop?
C) What is the average change in flow rate when pressure drop decreases by 5 in.?

A. 0.78 and 1.255.

B.  0.095

C. -0.475

Step-by-step explanation:

The given regression line is

y=-0.17+0.095x

A.

The true average flow rate for a pressure drop of 10 inch can be computed by putting x=10 in above equation.

y=-0.17+0.095*10

y=-0.17+0.95

y=0.78

The true average flow rate for a pressure drop of 10 inch is 0.78.

The true average flow rate for a pressure drop of 15 inch can be computed by putting x=15 in above equation.

y=-0.17+0.095*15

y=-0.17+1.425

y=1.255

The true average flow rate for a pressure drop of 15 inch is 1.255.

B.

The slope represents average change in y due to unit change in x.

So, the true average change in flow rate associated with a 1 inch increase in pressure drop is 0.095(1)= 0.095.

C.

When pressure drops decreases by 5 in. then the average change in flow rate is 0.095(-5)=-0.475.