Suppose a random sample of 100 U.S. companies taken in 2005 showed that 21 offered high-deductible health insurance plans to their workers. A separate random sample of 120 firms taken in 2006 showed that 30 offered high-deductible health insurance plans to their workers. Based on the sample results, can you conclude that there is a higher proportion of U.S. companies offering high-deductible health insurance plans to their workers in 2006 than in 2005? Conduct your hypothesis test at a 0.05 significance level.
a. State the null and alternate hypotheis
b. What is the level of significance?
c. What is the critical value?
d. Compute the value of the test statistic
e. What is your decision regarding the null hypothesis? Interpret the result.