In 2005 the New Jersey Adult Tobacco Survey found that 22.5% of 464 blacks surveyed said that they smoked cigarettes while 18.3% of 2449 white respondents reported smoking.
a) Create a 90% confidence interval for the difference in the percentage of smokers between black and white adults in New Jersey.
b) Does this survey indicate a race-based difference in smoking among American adults? Explain, using your confidence interval to test an appropriate hypothesis.
c) What alpha level did your test use?