As part of quality control, a pharmaceutical company tests a sample of manufacturer pills to see the amount of active drug they contain is consistent with the labelled amount. That is, they are interested in testing the following hypotheses:
H0:μ=100H0:μ=100 mg (the mean levels are as labelled)
H1:μ≠100H1:μ≠100 mg (the mean levels are not as labelled)
Assume that the population standard deviation of drug levels is 55 mg. For testing, they take a sample of 1010 pills randomly from the manufacturing lines and would like to use a significance level of α=0.05α=0.05.
They find that the sample mean is 104104 mg. Calculate the zz statistic.