Why is it desireable to have the explanatory variables sprea

Why is it desireable to have the explanatory variables spread out to test a hypothesis regarding B1 or construct confidence intervals about B1?

a. so the mean of b1 is larger

b. so the mean of b1 is smaller

c. so the standard deviation of b1 is larger

d. so the standard deviation of b1 is smaller

Solution

it is desirable to have the explanatory variables spread out to test a hypothesis regarding B1 or construct confidence interval about B1 because the mean of b1 is smaller as this is the only way to go for the hypothesis.