1. Given tan X is normally distributed with a mean of 0.545 and a standard deviation of 0.155, calculate the probability that X exceeds 0.395
2. A glass jar contains 15 marbles, from which 7are blue colored and the rest are known to be black. If five marbles are drawn from the jar without replacement, what is the probability of obtaining 3 black marbles or more?
3. In an inventory analysis it was concluded that, on the average, demands for a certain item were made 5 times per day. What is the probability that on the next 2 days this item is request not more than five times?