Advertisements claim the average nicotine content of a certain kind of cigarette is 0.30 mg. suspecting that this figure is too low; a consumer protection service takes a random sample of 15 of these cigarettes from different production lots and find their nicotine content has a mean of 0.33mg with a standard deviation of 0.18 mg. Is the advertisements claim true? use alpha=0.05

Solution:

Hypotheses:

Null:

Alt:

The critical value:

The test statistics:

Decision about null hypothesis and findings/ Conclusion: