Fitting a straight line to a set of data yields the predicti

Fitting a straight line to a set of data yields the prediction line = 7 + 9Xi. The value of X used to find the prediction line range from 7 to 33. Should this model be used to predict the mean value of Y when X equals 8? Should this model be used to predict the mean value of Y when

Solution

a)

Yes, because 8 is between 7 and 33.

b)

No, because -8 is not between 7 and 33.

c)

No, because 0 is not between 7 and 33.

[This one could be \"not enough information\", because 0 is not far off from the lower bound, which is 7. It depends on what criteria you use in class, and not all use the same criteria.]

d)

Yes, because 32 is between 0 and 33.