final_review - Final- Review Problem 1 The time X that a...

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Final- Review Problem 1 The time X that a technician requires to fix an air-conditioning unit has a roughly normal distribution with μ = 1 hour and σ = 1 hour. Your company operates 70 of these units. a) What are the mean and standard deviation of the sample mean x of these 70 units? Round your answers to four decimal places if necessary. b) What is the probability that that the average maintenance time x of these 70 units exceeds 50 minutes? Use your final answers from part a. Round your final answer to four decimal places.
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Problem 2 Tom and George are playing in the club golf tournament. Their scores vary as they play the course repeatedly. Tom’s score X has the N(110, 10) distribution, and George’s score Y varies from round to round according to the N(100, 8 distribution). Their scores are independent. a) What is the mean of (X-Y)? What is the standard deviation of (X-Y)? Round your answers to four decimals if necessary. b) What is the probability that Tom will score lower than George. Use your final answers from part a. Round your final answer to four decimal places.
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Problem 3 a) The mean debt level of a sample of 1280 borrowers $18,900. The population distribution is roughly normal. The population standard deviation σ = $49,000. The population distribution is roughly normal. Find a 95% confidence interval for the mean debt level of all borrowers. Round
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final_review - Final- Review Problem 1 The time X that a...

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