You are researching global warming for a policy brief. You use a dataset on global climate that contains the variables below. Variable Description Month, Year NCDC global temp anomaly v.1901-2000 Degrees Celsius God Aerosol Optical Depth at 550nm mei Multivariate ENSO Index tsil Total Solar Irradiance, W/m2 co2globe Global average marine surface CO2, ppm colanom Global CO2 anomaly, ppm For a-c, use 2 Exhibit 2 regress nodetemp myear and tsil mei co2globe colanom Source df MS Number of obs 372 F (6, 365) 166 . 54 Model 9. 75282068 6 1. 62547011 Prob > F 0 . 0000 Residual 3. 56240235 365 . 009760006 R-squared II 0 . 7325 Adj R-squared 1. 7281 Total 13 . 315223 371 . 035890089 Root MSE 09879 nodctemp Coef. Std. Err. P>ItI [958 Conf. Interval] myear 5. 55e-06 0005909 0. 01 0. 993 . 0011564 0011675 aod -1. 412768 . 2037926 6.93 0 . 000 -1. 813523 -1 . 012013 tsil 0830138 0128432 5. 46 0. 000 0577578 108269 mei . 0643313 . 005989 10. 74 0 . 000 0525539 0761086 co2globe . 0139817 . 0034599 1 . 04 0. 000 0071778 . 0207856 colanom - . 0030429 . 0054685 -0 . 56 0. 578 - . 0137968 - 0077109 _cons 118 . 0512 17. 52055 6. 74 0. 000 152 . 5051 83.59735 a. Identify (do not interpret; just list) the statistically significant variables. Use alpha=.05. (3 pts) b. Interpret the coefficient on co2globe (note: use "unit" to describe co2globe changes and degrees Celsius for god,global temperature) (3 pts) Is the regression coefficient on co2globe statistically significant? Show all 5 steps of the hypothesis test. Use alpha=.05 (5 pts) You decide to run a VIF diagnostic test. What would you be concerned about if you decided to run this test? State the term and its meaning (2 pts) What can you conclude about your model, given the results of the yif command from Exhibit 3? (3 pts) Exhibit 3 vif variable VIF 1/VIF co2anom 250 .06 - 003999 myear 153 .47 0 . 006516 co2globe 100 .73 0. 009928 aod 1 . 37 0. 729605 mei 1 . 30 0 . 766924 tsil 1 . 25 0 . 798298 Mean VIF 84 . 70 f. You remove the variables myear and co2anom and rerun the regression including the beta (standardized coefficient). Given the output in Exhibit 4, which of the coefficients has the largest effect on temperature? How do you know? (3 pts). g. Why was it helpful to rerun the regression adding the beta? (2 pts) Exhibit 4