I NEED THIS QUESTION AS SOOON AS POSSIBLE, IT'S URGENT, PLZ DON'T COPY IT FROM ANYWHERE TYPE YOUR ORIGINAL CONTENT, I'LL UPVOTE YOUR WORK.

Question 4. Assume that log prices follow a random walk with drift: Pt = l + pt-1 + Et; Et ~ iidN(0,0%). (a) Given that the sign of log returns is considered for testing stock price predictability, describe a possible test and discuss the effect of u on testing. [20 marks] (b) Propose an estimator of the test based on a sample of n+ 1 returns and justify it. [15 marks] Question 4. Assume that log prices follow a random walk with drift: Pt = l + pt-1 + Et; Et ~ iidN(0,0%). (a) Given that the sign of log returns is considered for testing stock price predictability, describe a possible test and discuss the effect of u on testing. [20 marks] (b) Propose an estimator of the test based on a sample of n+ 1 returns and justify it. [15 marks]