Question

In commercials for oral hygiene products such as toothpaste, mouthwash, and whitening strips, you will sometimes hear claims like "over 9 out of 10 dentists recommend (whatever is being advertised)." Why not all 10? Why does it seem like there is always one dentist who doesn't like the product? The answer is that the advertiser who made the commercial most likely doesn't mean that, literally, 10 dentists were asked and one dentist indicated that he or she would not recommend the product. What the advertiser is really doing is making a claim about a population proportion. How could the advertiser make this claim using marketing research? One way is to conduct a hypothesis test to determine if the true proportion of dentists who would recommend the product is greater than 0.90. Which of the following sets of hypotheses would allow the advertiser to conduct this test?

H subscript 0 : space p space equals 0.90 H subscript 1 : space p space not equal to 0.90

H subscript 0 : space mu space less or equal than space space 0.90 H subscript 1 : space mu space greater than space 0.90

H subscript 0 : space p space less or equal than space 0.90 H subscript 1 : p space greater than space 0.90

H subscript 0 : space mu space equals space space 9 H subscript 1 : space mu space not equal to space 9

H subscript 0 : space mu space greater than space space 9 H subscript 1 : space mu space less or equal than space space 9

H subscript 0 : space p space less than space 0.90 H subscript 1 : p space greater or equal than space 0.90

Answer 1

Solution:

This a right (One) tailed test.

The null and alternative hypothesis is,  

H subscript 0 : space p space less or equal than space 0.90 H subscript 1 : p space greater than space 0.90

Ho: p 0.90

Ha: p 0.90