Question

Most air travellers now use e-tickets. Electronic ticketing allows passengers to not worry about a paper ticket, and it costs the airline companies less to handle than paper ticketing. However, in recent times, the airlines have received complaints from passengers regarding their e-tickets, particularly when connecting flights and a change of airlines were involved. To investigate the problem, an independent agency contacted a random sample of 20 airports and collected information on the number of complaints the airport had with e-tickets for the month of March. The information is reported below:

18	13	11	13	16	16	18	16	17	13
13	15	18	13	17	18	13	17	17	14

At the 0.01 significance level, can the agency conclude that the mean number of complaints per airport is less than 17 per month?

a. What assumption is necessary before conducting a test of hypothesis?

(Click to select)  The population of complaints follows a normal probability distribution.  The population of complaints not follows a normal probability distribution.  The population of complaints follows a uniform probability distribution.

b. Not available in Connect.

c. Conduct a test of hypothesis and interpret the results.

H₀ : μ ≥ 17; H₁ : μ < 17;  (Click to select)  Reject  Accept  H₀ if t <  . (Round the final answer to 3 decimal places.)

The value of the test statistic is  . (Negative answer should be indicated by a minus sign. Round the final answer to 2 decimal places.)

(Click to select)  Reject  Do not reject  H₀. There is  (Click to select)  not enough  enough  evidence to conclude that the mean number of complaints is less than 17

Answer 1

The statistical software output for this problem is:

Hence,

a) The population of complaints follows a normal probability distribution.

c) H0 : μ ≥ 17; H1 : μ < 17

Reject Ho if t < -2.539

Test statistic = -3.41

Reject  H0. There is enough  evidence to conclude that the mean number of complaints is less than 17