Q 131

According to a 2009 Lawyers.com survey,only 35% of adult Americans had a will (The Wall Street Journal,December 12,2011).Suppose a recent survey of 250 adult Americans found 100 adults with wills.
a.Specify the competing hypotheses to determine whether the proportion of adult Americans who have a will differs from the proportion reported for 2009.
b.Calculate the value of the test statistic and the p-value.
c.At the 5% significance level,is the proportion different? Explain.

Q 132

A real estate investor thinks the real estate market has bottomed out.One of the variables he examined to arrive at this conclusion was the proportion of houses sold at or above the asking price.In 2010,the proportion of houses sold at or above the asking price was 14%.The real estate investor takes a random sample of 40 recently sold houses and finds that nine of them are selling at or above the asking price.
a.Specify the population parameter to be tested.
b.Specify the null and alternative hypotheses to determine whether the proportion of houses sold at or above the asking price has increased.
c.Calculate the value of the test statistic and the p-value.
d.At the 10% significance level,can you conclude that the proportion of houses sold at or above the asking price has increased?

Q 133

A doctor thinks he has found a miraculous cure for rheumatoid arthritis.He thinks it will cure more than 50% of all cases within a year of first taking the drug.To test his drug,he runs a clinical trial on 400 patients with rheumatoid arthritis.He finds that 208 of the patients are symptomfree within a year.
a.Specify the null and alternative hypotheses to determine whether the proportion of patients that are cured by the drug exceeds 50%.
b.Calculate the value of the test statistic,and find the critical value at a 5% significance level.
c.At the 5% significance level,can you conclude that the percentage of patients who are cured by the drug exceeds 50%?