Can you please help me with this problem?

(Academic Performance Regression) Consider the following model in which course grade is a function of hours studied score = 50 + lstudy + u (a) Suppose you get a random sample from the population that consists of {scarab study} for z' = 17 2, . . . ,n. Also, you conrmed that study has variation in this sample. What is an additional assumption needed for OLS to be unbiased? (b) Using OLS you obtain .3??? = 50 + lostudy, n = 100, R2 = 0.20. From this result, can you claim that 131 : 10? Explain. (Hint: think sample vs. population). (c) The jth observation takes on the values scorej : 75 and studyj : 3. Based on the estimated result in (b), calculate the residual for this observation