MATH 350 Homework 09

  1. Consider the following table giving counts for the types of each coffee purchased at my favorite coffee shop within a weekend.
    Small Medium Large
    regular 19 23 22
    decaf 20 15 17
    1. Find the joint distribution of the coffee size and type (regular or decaf).
    2. Find the marginal distribution of coffee size.
    3. Find the marginal distribution of coffee type.
  2. Suppose the joint density function for X,YX, Y is f(x,y)=x+yf(x, y) = x + y for 0x10 \leq x \leq 1 and 0y10 \leq y \leq 1.
    1. Find the marginal density function for XX, f(x)f(x).
    2. Find the marginal density function for YY, f(y)f(y).
    3. Are XX and YY independent?