Question

Sixteen men enter an elevator which has a carrying capacity of 1164 kg. Suppose that the men’s weights can be considered as independent normal random variables with mean 70 kg and standard deviation 10 kg. Then the probability of the carrying capacity being exceeded is  

Group of answer choices

41%

27.0%

67.4%

13.6%

7.2%

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Question 58 1 pts

United Airlines Flight 433 is a nonstop flight from Boston’s Logan airport to San Francisco International Airport. An important factor in scheduling such flights is the actual airborne flying time from takeoff to touchdown. Suppose the airborne flying time is distributed as normal with mean 370 minutes and standard deviation 16 minutes. 31 records of the times (in minutes) that it takes flight 433 to fly from Boston’s Logan airport to San Francisco International Airport are randomly selected from the 2016 database. What is the sampling distribution of the average airborne flying time?

Group of answer choices

μ ∼ N ( 370 , 2.87 ) i.e. the population is normal with mean 370 and standard deviation 2.87.

x ¯ ∼ t ( 30 ) i.e. the sample mean is t distributed on 30 degrees of freedom.

x ¯ ∼ N ( 370 , 16 ) i.e. the sample mean is normal with mean 370 and standard deviation 16.

x ¯ ∼ N ( 370 , 2.87 ) i.e. the sample mean is normal with mean 370 and standard deviation 2.87.

μ ∼ t ( 31 ) i.e. the population mean is t distributed on 31 degrees of freedom.

Answer 1