please answer both the questions. please solve it theoretically don't use r code

1. The Surf-excel company uses a machine to ll boxes with soap powder. Assume that the net weight of the boxes of soap is normally distributed with mean 15 ounces and standard deviation 0.8 ounces. 25% of the boxes will be heavier than a certain net weight a) and 75% of the boxes will be lighter than this net weight. Find a) . 2. In the large city A,20 per cent of Random sample of 900 School children had defective eye sight. In the large city B, 15 percent of random sample of 1600 school children had the same defective. Is this Difference between the two Proportions Significant? Obtain 95% confidence limits of the difference in the population proportions