Researchers simulated boarding times for airline passengers using the normal distribution. They created different statistical models by varying the boarding strategies used, the amount of luggage passengers had, the capacity of the plane, how full the flight was, and the layout of the seats on the plane. One of the normal distribution models used for boarding times had a mean of 6.9 minutes and a standard deviation of 1.5 minutes. Use the normal distribution explorer app in our course book (under the Tools section) to answer the following questions. There may be some slight differences in answers between the tool and this quiz, so choose the answers closest to what the tool provides. Using the normal distribution model defined above: the middle 95% of boarding times are modelled to be between around [ Select ] and [ Select ] minutes. A boarding time of 8 minutes would be [ Select ] , as it has a [ Select ] tail proportion of around [ Select ] . Another boarding time of 5.3 minutes would be [ Select ] unusual than the first boarding time of 8, as its tail proportion is [ Select ] . If the model was changed, and the standard deviation was bigger, the middle 95% of boarding times under this model would become a [ Select ] interval.

Suppose the commute times for employees of a large company follow a normal distribution. If the mean time is 22 minutes and the standard deviation is 5 minutes, 95% of the employees will have a travel time within which range?A.17.25 minutes to 26.75 minutesB.17 minutes to 27 minutesC.12 minutes to 32 minutesD.7 minutes to 37 minutesSUBMITarrow_backPREVIOUS

The manager of a grocery store has taken a random sample of 100 customers to determine whether or not the mean waiting time of all customers is significantly more than 3 minutes. She observes that the average length of time it took the customers in the sample to check out was 3.1 minutes. The population standard deviation is known to be 0.5 minutes.

Accordingto statistics released by the Department of Civil Aviation, the average delayof flights is equal to 16.8 minutes, flight delays are assumed to follow anormal distribution.  However, from asample of 50 flights, the average delay was estimated to be 19.5 minutes andthe sample standard deviation was 6.6 minutes.Conducta hypothesis test to disprove the claim that the average delay is equal to 16.8minutes at a= 0.01.

The manager of a computer shop is recording the time taken for customers to decide of which computer and accessories they buy from the time they enter the store. From the previous data, it is known that the average ‘decision’ time was 45 minutes. The manager assumes a normally distributed population with a standard deviation of 10 minutesa)  What is the probability that a customer will take more than 60 minutes?

The amount of time that customers wait in line during peak hours at one bank is normally distributed with a mean of 12 minutes and a standard deviation of 2 minutes. What is the probability that a customer will wait under 14 minutes?