Let x be a random variable that represents the pH of arterial plasma (i.e., acidity of the blood). For healthy adults, the mean of the x distribution is ? = 7.4.† A new drug for arthritis has been...

Letx be a random variable that represents the pH of arterial plasma (i.e., acidity of the blood). For healthy adults, the mean of thex distribution is ? = 7.4.† A new drug for arthritis has been developed. However, it is thought that this drug may change blood pH. A random sample of 41 patients with arthritis took the drug for 3 months. Blood tests showed that x = 8.8 with sample standard deviations = 3.5. Use a 5% level of significance to test the claim that the drug has changed (either way) the mean pH level of the blood.