30. A trading firm makes 10,000 trades per day. On each trade it has a 35 percent chance of making $2 and a 65 percent chance of losing $1. (a) What is the mean and standard deviation of its daily returns? (b) Assuming that with this many trades the firm's returns are approximately normally distributed use a table for the standard normal distribution (or find some other method) to estimate the probability that the firm will lose money on any given day