1.1 Linearity of regression models means that... - a. the model is required to be linear in the parameters but not necessarily linear in the variables. - b. the model is required to be linear in the variables but not necessarily linear in the parameters. - c. the X variable(s) can only be expressed with an exponent of one. - d. all independent variables must appear only once on the right side of the equation, and with an exponent of one. - e. the relationship between Y and X is well approximated by a straight line 1.2 Select the correct option. - a. The Jarque-Bera test considers the skewness and kurtosis of the error terms. - b. The Jarque-Bera test is a test of joint standard deviation and kurtosis of the distribution of residuals. - c. The Jarque-Bera test considers the skewness and kurtosis of the residuals. -d. The Jarque-Bera test considers the standard deviation and kurtosis of the residuals. -e. The Jarque-Bera test is a test of joint skewness and kurtosis of the distribution of stochastic error terms. 1.3 In general, hypothesis testing, degrees of freedom are given by: - a. k-n - b. k-a - c. n-k - d. n-2 - e. n-1