The Pollution Control Board requires that potable water should contain no more than 0.025 mg/l of lead. A random sample of 150 water specimens from different parts of the country shows an average lead...

The Pollution Control Board requires that potable water should contain no more than 0.025 mg/l of lead. A random sample of 150 water specimens from different parts of the country shows an average lead content of 0.038 mg/l and a standard deviation of 0.10 mg/l. Test the results to determine whether
the regulation is followed. The significance level is 0.05.