Problem:
The quality of the drinking water must be monitored as often as possible. One variable of concern is the
pH level, which measures the alkalinity or acidity of the water. A pH below 7.0 is acidic while a pH above 7.0 is
alkaline. A pH of 7.0 is neutral. A water-treatment plant is targeting higher than 8.0 pH. Based on 16 random
water samples, the mean and standard deviation were found to be: * = 7.6 and s = 0.4. Test the claim using 5%
level of significance.
Note: Follow the steps in hypothesis testing using traditional or critical value method.​