1. A balanced coin is flipped 400 times. Determine the number x such that the probability that the number of heads is between 200 - x and 200 + x is approximately .80.
2. A noodle machine in Spumoni's spaghetti factory makes about 5 percent de- fective noodles even when properly adjusted. The noodles are then packed in crates containing 1900 noodles each. A crate is examined and found to contain 115 defective noodles. What is the approximate probability of finding at least this many defective noodles if the machine is properly adjusted?