Data collected in 2015 by the Behavioral Risk Factor Surveillance System revealed that in the state of New Jersey, 27.3% of whites and 47.2% of blacks were cigarette smokers. Suppose these proportions were based on samples of 3607 whites and 485 blacks.
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?