(5pts) You are interested in estimating 9 = [11 #2, where Y1~Norm(p1, 50) and Y2~Norm(p2, 100) and Y1, Y2 are independent. You can afford a total of 100 observations. How many observations should you draw from Y1 and Y2 respectively to ensure the variance of E? is the lowest? Based on the estimator you propose, write the 95% confidence interval of E3