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A recent study concluded that 36% of fish in a certain river were mature females. A sample of 200 fish are taken randomly from the same river. What is the probability that the sample proportion of mature female fish will be within +/-.05 of the actual population proportion

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Jacob Fry

Numerade educator

Questions 16-17. Consider a random sample ( X_{1}, X_{2}, ldots, X_{9} ) selected from a normal population with mean ( mu ) and variance ( sigma^{2} ). Let ( ar{X} ) be the sample mean and ( s^{2} ) be the sample variance. 17. Which range of values includes ( P(ar{X}>mu+s) ) ? (a) 0 and 0.005 ( sqrt{ } ) (b) 0.005 and 0.01 (c) 0.01 and 0.02 (d) 0.02 and 0.025 (e) 0.025 and 1

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Qudsiya Anis

Numerade educator

The probability that your call to a service line is answered in less than 30 seconds is 0.75. Assume that your calls are independent. What is the probability that you must call six times in order for two of your calls to be answered in less than 30 seconds?

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Kirsty Gledhill

Numerade educator

Let X and Y be uniform random variables on the interval (0, 1). If X and Y are independent, the variance of 𝑋 − 2𝑌 is? If the covariance of X and Y is 𝑐𝑜𝑣(𝑋, 𝑌) = 1/12, the variance of 𝑋 − 2𝑌 is?

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Robin Corrigan

Numerade educator

An insurance company handling malpractice cases is interested in estimating the average amount of claims against physicians of a certain specialty. The company plans to select a large sample and calculate the sample average X. Suppose the insurance company decides to use $6,000 as the standard deviation on the amount of claims. Suppose the company selects a random sample of 36 cases. The width of a 95% confidence interval for the average amount of claims is closest to

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Jacob Fry

Numerade educator

Let ( X_{1}, X_{2}, ldots, X_{100} ) and ( Y_{1}, Y_{2}, ldots, Y_{81} ) be two independent random samples from the same population with mean 50 and standard deviation 40 . Let ( ar{X} ) and ( ar{Y} ) be the sample means, respectively. The probability ( P(ar{X}-ar{Y}>5) ) is closest to

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T. L.

Numerade educator

Let and be two independent random samples from the same population with mean 50 and standard deviation 40. Let and be the sample means, respectively. The probability is closest to

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T. L.

Numerade educator

Suppose 𝑃(𝐴 ∪ 𝐵) = 0.7 and 𝑃(𝐴 ∪ 𝐵^c) = 0.9. Then 𝑃(𝐴) =

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Hoan Nguyen

Numerade educator

Let 𝑋1, 𝑋2, ... , 𝑋𝑛 be a random sample from a normal distribution with mean 2 and standard deviation 2. If 𝑃(1.9 ≤ 𝑋̅ ≤ 2.1) = 0.95, the smallest value of n is closest t

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Hoan Nguyen

Numerade educator

Assume that the probability of a child being a boy or a girl is 1/2 , and that genders are independent events. In a family of four children, the probability that three of them have the same gender is?

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Ayesha Z.