math 411 homework9

# math 411 homework9 - X and Y are independent with EX = 1 EY...

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Department of Mathematics Fall 2011 Volodymyr Nekrashevych Math 411 — Problem Set 9 Issued: 11.15 Due: 11.23 9.1. 20 people get on an elevator on the ﬁrst ﬂoor of a seven-story building. Each gets oﬀ at one of the six higher ﬂoors chosen at random. What is the expected number of stops the elevator makes? 9.2. Suppose we draw 5 cards out of a deck of 52. What is the expected number of diﬀerent suits in our hand? 9.3. Suppose
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Unformatted text preview: X and Y are independent with EX = 1, EY = 2, var( X ) = 3, and var( Y ) = 1. Find the mean and variance of 3 X + 4 Y-5. 9.4. Suppose X takes on the values-2 ,-1 , , 1 , 2 with probability 1 / 5 each, and let Y = X 2 . (a) Find cov( X,y ). (b) Are X and Y independent. 9.5. Let X be binomial(4, 1/2) random variable. Use Chebyshev’s inequal-ity to estimate P ( | X-2 | ≥ 2) and compare with exact probability....
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## This note was uploaded on 02/13/2012 for the course MATH 411 taught by Professor Staff during the Fall '08 term at Texas A&M.

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