A national air traffic control system handled an average of 47,284 flights during 29 randomly selected days in a recent year. The standard deviation for this sample is 6,255 flights per day. Complete parts a through c below.

a. Construct a 99% confidence interval to estimate the average number of flights per day handled by the system.

The 99% confidence interval to estimate the average number of flights per day handled by the system is from a lower limit of

nothing

to an upper limit of

nothing

.

(Round to the nearest wholenumbers.)

b. Suppose an airline company claimed that the national air traffic control system handles an average of50,000 flights per day. Do the results from this sample validate the airlinecompany's claim?

A.

Since the 99% confidence interval contains50,000, it can be said with 99% confidence that the sample validates the airlinecompany's claim.

This is the correct answer.

B.

Since the 99% confidence interval does not contain50,000, it can be said with 99% confidence that the sample validates the airlinecompany's claim.

C.

Since the 99% confidence interval contains50,000, it cannot be said with 99% confidence that the sample validates the airlinecompany's claim.

Your answer is not correct.

D.

Since the 99% confidence interval does not contain50,000, it cannot be said with 99% confidence that the sample validates the airlinecompany's claim.

c. What assumptions need to be made about thispopulation?

A.

Since the sample size is not greater than or equal to30, one needs to assume that the population follows theStudent's t-distribution.

B.

Since the sample size is not greater than or equal to30, one needs to assume that the population follows the normal probability distribution.

This is the correct answer.

C.

Since the sample size is not greater than or equal to30, one needs to assume that the population distribution is not very skewed to one side.

Your answer is not correct.

D.

Since the sample size is not greater than or equal to30, one needs to assume that the population distribution is skewed to one side.