Question

17. A major airline company is concerned that its proportion of late arrivals has substantially increased in the past month. Historical data shows that on the average 18% of the company airplanes have arrived late. In a random sample of 1,250 airplanes, 250 airplanes have arrived late. If we are conducting a hypothesis test of a single proportion to determine if the proportion of late arrivals has increased: What is the correct statement of null and alternative hypothesis?
A. H₀: p <.18 and H_A: p ³.18
B. H₀: p £.18 and H_A: p >.18
C. H₀: p =.18 and H_A: p ¹ .18
D. H₀: p >.18 and H_A: p £.18
E. H₀: p £.20 and H_A: p >.20

Answer 1

The alternative hypothesis is the claim of the test and the null hypothesis is the opposite of that.

The claim in this problem is “the proportion of late arrivals has increased” therefore the opposite of the claim is “the proportion of late arrivals has not increased that means either equal or decreased”.

The null hypothesis would be:

B. H₀: p £.18 and H_A: p >.18

Note: The sign £ is not appropriate in this situation and no option gives the correct option. You should talk to your professor regarding this.