Q. Which of the following is not an assumption that must be met for the least squares estimations to be valid? Why?

a) the probability distribution of the error terms is normally distributed.

b) on average, the error term is 0.?

c) the variance of y is equal at every value of x.

d) none of the above.

Q. Suppose the sample slope measuring the relationship between amount of sleep (x, in hours) and number of yawns by students in 8AM classes (y) for 100 UGA students is computed to be -0.82. From this you can appropriately conclude that:

a) b1 cannot be positive.

b) there is no linear relationship between the two variables.

c) the least squares line slopes downward.

d) none of the above

e) more than one of the above