The Carolina Tobacco Company advertised that its best-selling nonfiltered cigarettes contain 40 milligrams of nicotine or less, but Consumer Advocate magazine ran tests on 10 randomly selected cigarettes and found the amounts (in milligrams) shown below.
    47.3 39.3 40.3 38.3 46.3
    43.3 42.3 49.3 40.3 46.3

We can assume that the amount of nicotine in all cigarettes is normally distributed. Use a significance level of 0.05 to test the magazine’s claim that the mean nicotine content of the Carolina Tobacco Company’s cigarettes is greater than 40 milligrams.