Author:
Christine Farr

2. Imagine you are in a game show. There are 4 prizes hidden on a game board with 10 spaces. One prize is worth $100, another is worth $50, and two are worth $10. You have to pay $20 to the host if your choice is not correct. Let the random variable x be the winning. Show all work. Just the answer, without supporting work, will receive no credit.

(a) What is your expected winning in this game?

(b) Determine the standard deviation of x. (Round the answer to two decimal places)

3. Mimi just started her tennis class three weeks ago. On average, she is able to return 20% of her opponent’s serves. Assume her opponent serves 8 times. Show all work. Just the answer, without supporting work, will receive no credit.

(a) Let X be the number of returns that Mimi gets. As we know, the distribution of X is a binomial probability distribution. What is the number of trials (n), probability of successes (p) and probability of failures (q), respectively? (5 pts)

(b) Find the probability that that she returns at least 1 of the 8 serves from her opponent

(c) How many serves can she expect to return?

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