A random variable, X, has a population mean, µ = 155, and a population standard deviation,...

A random variable, X, has a population mean, µ = 155, and a population standard deviation, σ = 10. What is the probability that X is more than 180?

Answer

PART II. A random variable, X, has a population mean, µ = 155, and a population standard deviation, σ = 10. To study the population, a random sample of 64 observations is collected and data is recorded. What is the probability that a sample mean will exceed 180?

Answer

Using PART II information, what is the probability that a sample mean will exceed 158?

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In PART I, what assumption did you make about the random variable's distribution?

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In PART II, what assumption did you make about the random variable's distribution?

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Why? Answer

Solutions

Expert Solution

In part first distribution is normal ( 155,10)

In part second distribution is normal ( 155,10/√64) i.e. (155,10/8)=(155,1.25)

Because for sampling distribution standard deviation will be /√n

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orchestra answered 1 year ago

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