It is estimated that 0.5% of the callers to the Customer Service department of Dell Inc. Will receive a busy signal. A) Show that this binomial distribution can be approximated with a standard normal distribution. b) What is the probability that of today's 1,200 callers, at least 5 received a busy signal?

Expresa commuter train leaves downtown sation and travels at a average speed of 55 miles per hour towards the north side sation, which is 50miles away. thirty minutes later, express commuter train #7 leaves north side and travels at a average speed of 35miles per hour towards downtown sation. at the moment the two trains pass each other, how far(in miles) is train #12 from the downtown sation and how long(in minutes) has the #12 train been traveling