In: Statistics and Probability
The national health organization warns that 30% of the middle school students nationwide have been drunk. A local health agency randomly and anonymously surveys 100 of the middle school students in its city and finds that only 21 of them report having been drunk. |
Create a 95% confidence interval for the proportion of the city's middle school students who have been drunk. |
Is there any reason to believe that the national level of 30% is not true for the middle school students in the city? Test at 1% significance level. |