Measurement of water intake, obtained from a sample of 17 rats that had been injected with a sodium chlorine solution, produced a mean of 31 cubic centimeters and a standard deviation of 6.2 cubic centimeters. Given that the expected water intake for noninjected rats observed over a comparable period of time is 22 cubic centimeters, do the data indicate that injected rats drink more water that noninjected rats ? Test at 5% significance. Find a 90% confidence interval for the mean water intake for injected rats.