A company believes that it controls more than 30% of the total market share for one of its products.To prove this belief,a random sample of 144 purchases of this product is contacted.It is found that 50 of the 144 purchased this company's brand of the product.If a researcher wants to conduct a statistical test for this problem,the test would be _______.
A) a one-tailed test
B) a two-tailed test
C) an alpha test
D) a finite population test
E) a finite sample test

Question

Quizplus · Accepted Answer

A one-tailed test is appropriate in this case because the company is interested in proving that it controls more than 30% of the market share, not simply whether its market share is different from 30%. A two-tailed test would be appropriate if the company wanted to show that its market share was either greater than or less than 30%. Alpha and finite population tests are not relevant to this problem. While it is a finite sample test, the more specific answer is that it is a one-tailed test.

A Company Believes That It Controls More Than 30% of the Total