Question 9 (1 point) A regression model can be thought of as estimating the best-fitting line through the data. True False Question 10 (1 point) var (bX) = b + var(X) True False Question 11 (2 points) In a regression model the ratio of an estimated coefficient to its standard error is called a t statistic. can be used to test if the coefficient is statistically significant. O will be close to O if the null hypothesis is true all of the above