Exam 10: Testing Hypotheses About Proportions

A survey claims that 7 out of 10 customers recommend Western Drugs for pharmacy issues. To test this claim, a random sample of 100 customers is obtained from the list of Rewards customers. Of these 100 customers, 75 indicate that they recommend using Western Drugs for pharmacy needs. We would like to know if this claim is accurate.

A company that sells eco-friendly cleaning products is concerned that only 19.5% of people who use such products select their brand. A marketing director suggests that the Company invest in new advertising and labeling to strengthen its green image. The Company decides to do so in a test market so that the effectiveness of the marketing Campaign may be evaluated. Based on data collected in the test market, the company Constructed a 98% confidence interval for the proportion of all consumers who might buy Their brand. The resulting interval is 16% to 28%. What conclusion should the Company reach about the new marketing campaign?

A survey claims that 7 out of 10 customers recommend Western Drugs for pharmacy issues. To test this claim, a random sample of 100 customers is obtained from the list of Rewards customers. Of these 100 customers, 75 indicate that they recommend using Western Drugs for pharmacy needs. We would like to know if this claim is accurate. State your conclusion using α = 0.05.

A report on the U.S. economy indicates that 28% of Americans have experienced difficulty in making mortgage payments. A news organization randomly sampled 400 Americans from 10 cities named the "fastest dying cities in the U.S." (Forbes Magazine, August 2008) and found that 136 reported such difficulty. Does this indicate that the Problem is more severe among these cities? The correct null and alternative hypotheses For testing this claim are

A national study report released by the Center for Studying Health System Change (HSC) in 2010, indicated that 20.9% of Americans were identified as having medical bill Financial issues. Many people in families with problems paying medical bills in 2010 Experienced severe financial consequences from their medical debt, with about two-thirds Reporting problems paying for other necessities and a quarter considering bankruptcy, the Study found. What if a news organization randomly sampled 400 Americans from 10 Cities and found that 90 reported having such difficulty. A test was done to investigate Whether the problem is more severe among these cities. The p-value for this test is

Top management of a large multinational corporation wants to create a culture of innovativeness and change. A consultant hired to assess the company's organizational Culture finds that only 15% of employees are open to new ideas and approaches toward Their work. Consequently the company conducts a program for employees in order to Reinforce the new corporate philosophy. Based on data collected after the program, the Finds the 95% confidence interval for the proportion of all employees open to new ideas To be 18% to 22%. What should the company conclude?

A company manufacturing computer chips finds that 8% of all chips manufactured are defective. In an effort to decrease the percentage of defective chips, management decides To provide additional training to those employees hired within the last year. After Training was implemented, a sample of 450 chips revealed only 27 defects. A hypothesis Test is performed to determine if the additional training was effective in lowering the Defect rate. Which of the following statement is true about this hypothesis test?