Mini test: Discrete Random Variable

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Mini test: Discrete Random Variable

Name: ____________ Student ID: ____________

1. The discrete random variable X has probability distribution given by

x –1 0 1 2 3

P(X = x) 1/5 a 1/10 a 1/5

Where a is a constant.

(a) Find the value of a. (4)

(b) Write down E(X). (2)

(c) Find Var(X ). (6)

The random variable Y = 6 − 2X.

(d) Find Var(Y). (3)

(e) Calculate P(X  Y). (5)