1. The mass of a box of washing powder produced by a factory is normally distributed with a mean of 840 grams and a standard deviation of 7.5 grams. If a random sample of 14 boxes of washing powder is selected, what is the probability that the mean mass is more than 845 grams?

2. Past records of a factory show that 4% of the candles produced are defective. What is the probability that out of a random sample of 150 candles, more than 3% are defective?