Problem: 1 A random sample of 13 milk packets was taken from a dairy company. Detected amount of lead was 0.02, 0.05, 0.06, 0.008, 0.072, 0.11, 0.01, 0.006, 0.05, 0.03, 0.07, 0.004 and 0.002 milligram per kilogram respectively. Test the hypothesis that the average of the selected sample units lies within the maximum permissible limit of lead in milk (0.02 milligram per kilogram) at 5% level of significance