Statistics
posted by Mike on .
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 20.822.0
1998 20.2 19.620.8
1999 20.3 19.621.0
2000 19.2 18.619.9
2001 20.0 19.420.6
2002 19.9 19.220.5
2003 19.1 18.519.8
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?

Whatever year the percent was less than the maximum of the confidence interval of 20%, 2000 and 2003.