Help putting equations into excel:

Assume that the traffic to the web site of Smileys People, Inc., which sells customized T-shirts, follows a normal distribution, with a mean of 4.5 million visitors per day and a standard deviation of 820,000 visitors per day.

(10 points) What is the probability that the web site has fewer than 5 million visitors in a single day?

(15 points) What is the probability that the web site has 3 million or more visitors in a single day?