A study found that highway drivers in one state traveled at an average speed of 62.5 miles per hour (MPH). Assume the population standard deviation is 6.3 MPH. Complete parts a through d below. a. What is the probability that a sample of 30 of the drivers will have a sample mean less than 61 MPH? (Round to four decimal places as needed.) b. What is the probability that a sample of 40 of the drivers will have a sample mean less than 61 MPH? (Round to four decimal places as needed.) c. What is the probability that a sample of 50 of the drivers will have a sample mean less than 61 MPH? (Round to four decimal places as needed.)
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5 MPH - Population standard deviation (σ) = 3 MPH - Sample size (n) = 30, 40, 50 - Sample mean (x̄) = 61 MPH Show more…
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A study found that highway drivers in one state traveled at an average speed of 61.6 miles per hour (MPH). Assume the population standard deviation is 5.8 MPH. Complete parts a through d below. a. What is the probability that a sample of 30 of the drivers will have a sample mean less than 60 MPH? P(x < 60) = 0.0655 (Round to four decimal places as needed.) b. What is the probability that a sample of 40 of the drivers will have a sample mean less than 60 MPH? P(x < 60) = 0.0409 (Round to four decimal places as needed.) c. What is the probability that a sample of 50 of the drivers will have a sample mean less than 60 MPH? P(x < 60) = (Round to four decimal places as needed.)
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