Refer to Exercise 5.86. Suppose that Z is a standard normal random variable and that Y is an independent 2 random variable with degrees of freedom. a Define W = Z/ Y . Find Cov(Z, W). What assumption do you need about the value of ? b With Z, Y , and W as above, find Cov(Y, W). c One of the covariances from parts (a) and (b) is positive, and the other is zero. Explain why.

Chapter 2 2.1 Statistics is all about data: (nothing but counts and measurement) Data- Qualitative: names, labels, etc. Ex. Gender survey Quantitative: numerical count (discrete), sibling survey (numerical discrete) Measurement (continuous), height survey (numerical continuous) Examples: Exam 1 (2012) Q. 14.) B Q. 15.) C 2.2 Other forms: ordinal variable ex. Level of lower back pain...