Annual income: The mean annual income for people in a certain city (in thousands of dollars)...

Annual income: The mean annual income for people in a certain city (in thousands of dollars) is

40, with a standard deviation of 28. A pollster draws a sample of 90 people to interview.

(a) What is the probability that the sample mean income is less than

38? Round the answer to at least four decimal places.

(b) What is the probability that the sample mean income is between

38 and 46

(d) Would it be unusual for the sample mean to be less than

38? Round the answer to at least four decimal places.

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Expert Solution

orchestra answered 1 year ago

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