Suppose that Y1, Y2, and Y3 are independent 2-distributed random variables with 1, 2, and 3 degrees of freedom, respectively, and that W1 = Y1 + Y2 and W2 = Y1 + Y3. a In Exercise 5.87, you derived the mean and variance of W1. Find Cov(W1, W2). b Explain why you expected the answer to part (a) to be positive.

1 STAT 145 Introduction to Statistics 1 Chapter 2 Organizing and Summarizing Data Terms ormulas 2.1 Organizing Qualitative Data Objectives: Group data in tables / Construct bar graphs and pie charts...