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Chapter 6: Q.12 (page 354)

Kids and toys Refer to Exercise 4. Calculate the mean of the random variable X and interpret this result in context.

Short Answer

Expert verified

On average there are 2.68 toys that are played with.

Step by step solution

01

Given Information

The probability distribution of the number X of toys played with by a randomly selected subject is as follows:

02

Explanation

The expected value is calculated by multiplying each possibility by its probability:

E(X)=鈭�xP(x)=0脳0.03+1脳0.16+2脳0.30+3脳0.23+4脳0.17+5脳0.11=2.68

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Most popular questions from this chapter

While he was a prisoner of war during World War II, John Kerrich tossed a coin 10,000times. He got5067heads. If the coin is perfectly balanced, the probability of a head is 0.5.

(a) Find the mean and the standard deviation of the number of heads in 10,000tosses, assuming the coin is perfectly balanced.

(b) Explain why the Normal approximation is appropriate for calculating probabilities involving the number of heads in 10,000tosses.

(c) Is there reason to think that Kerrich鈥檚 coin was not balanced? To answer this question, use a Normal distribution to estimate the probability that tossing a balanced coin 10,000times would give a count of heads at least this far from 5000(that is, at least5067 heads or no more than 4933 heads

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