Assume a researcher recruits 100 men and women being treated with morphine for pain to determine if there is a difference in the mean dosage of the medication needed to cause a decrease in clinical symptoms of pain, if the mean dosage for 50 men required to decrease their symptoms of pain is 24 mg with a standard deviation of 4.5 mg and the mean dosage for 50 women required to decrease their symptoms of pain is 18 mg with a standard deviation of 5.2 mg, the z value obtained while calculating the test statistic is approximately 6.17, suggesting there is a difference in the mean dosage of morphine at the 5% significance level.