Hypothesis Test for one population Mean (t-Test)
A certain prescription medicine is supposed to contain an average of 250 parts per million (ppm) of a certain chemical. If the concentration is higher than this, the drug may cause harmful side effects: if it is lower, the drug may be ineffective. the manufacturer runs a check to see if the mean concentration in a large shipment conforms to the target level of 250 ppm or not. A simple random sample of 100 portions is tested, and the sample mean concentration is found to be 247 ppm with a standard deviation of 12ppm. Is this evidence that the drug is ineffective at the significance level of.01