Question: Nicotine in cigarettes. To determine whether the mean nicotine content of a brand of cigarettes is greater than the advertised value of 1.4 mg, a health advocacy group tests

\[\begin{aligned} & {{H}_{0}}:\mu =1.4 \\ & {{H}_{A}}:\mu >1.4 \\ \end{aligned}\]

The calculated value of the test statistic is z =2.42.

a) Is the result significant at the 5% level?

b) Is the result significant at the 1% level?