Suppose that you choose three coins at random (without replacement) from a bag containing four 20p coins and five 10p coins. (i) Find the probability mass function of the random variable counting the number of 20p coins selected. (ii) Determine the total expected cash value of the three coins you get, giving your answer correct to the nearest penny. (b) Let ZZ be a discrete random variable with E(Z)=0E(Z)=0. Does it necessarily follow that E(Z3)=0E(Z3)=0? If yes, give a proof; if no, give a counterexample.

Suppose that you choose three coins at random (without replacement) from a bag containing four 20p coins and five 10p coins. (i) Find the probability mass function of the random variable counting the number of 20p coins selected. (ii) Determine the total expected cash value of the three coins you get, giving your answer correct to the nearest penny. (b) Let ZZ be a discrete random variable with E(Z)=0E(Z)=0. Does it necessarily follow that E(Z3)=0E(Z3)=0? If yes, give a proof; if no, give a counterexample.

College Algebra

7th Edition

ISBN:9781305115545

Author:James Stewart, Lothar Redlin, Saleem Watson

Publisher:James Stewart, Lothar Redlin, Saleem Watson

Chapter9: Counting And Probability

Section9.4: Expected Value

Problem 1E: If a game gives payoffs of $10 and $100 with probabilities 0.9 and 0.1, respectively, then the...

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