QUESTION 1 In this exercise we look again at the relationship between the look of instructors and their course evaluation. The dataset contains several variables, but for the purpose of this problem we are only considering course evaluations, beauty and age. Download the file at the following link Open the file in Excel and estimate the following three linear regression models (A) COURSE EVAL beta0 beta1 BEAUTY error (B) COURSE EVAL beta0 beta1 AGE error (C) COURSE EVAL betab + beta1 BEAUTY + beta2 AGE + error where COURSE EVAL: average course evaluation of the instructor BEAUTY beauty index of the instructor (between-2 and 2 with 0 representing average look) AGE: age (in years) of the instructors Answer the following questions Vladimir and Igor are identical twins and they both happen to be teachers at the same university based on model C, how much do you expect to be the difference in COURSE EVAL between them? Mario and Luigi are longtime college friends from the class of 1960 and they now happen to be teachers at the same university. COURSE EVAL relative to Luigi by Mario has always been considered the better looking of the two with a BEAUTY index of 1.9 while Luigi's index is 1.5. Based on model C, Mario is expected to have (type HIGHER or LOWER) What is the estimated effect of BEAUTY on COURSE EVAL in regression A? C? and in regression Comparing the estimates for regression A and C, do you find evidence that regression A might suffer from omitted variable blas? (type YES or NO) Comparing the estimated effect of AGE on COURSE EVAL in regression B and C. do you find evidence that regression B might Is the statistical significance (at 5%) of AGE in suffer from omitted variable blas? (type YES or NO) the two regressions different? (type YES or NO) Professor Wang has a beauty index of -1.5 and is 54 year old. What is the predicted course evaluation by model C for Professor