Question

The Centers for Disease Control (CDC) collects yearly statistics on drinking behavior in the United States by surveying a random sample of U.S. adults. The following data display the percent of adults aged 18 years and over who had 5 or more drinks in 1 day at least once in the given year.

Year Percent 95% confidence interval
1997 21.4 20.8-22.0
1998 20.2 19.6-20.8
1999 20.3 19.6-21.0
2000 19.2 18.6-19.9
2001 20.0 19.4-20.6
2002 19.9 19.2-20.5
2003 19.1 18.5-19.8
For which years (or year) above could you reject the null hypothesis that more than 20% of U.S. adults had 5 or more drinks in 1 day, at the .05 significance level?

There may be more than one correct answer.