A publisher has discovered that the number of words contained in a new manuscript is normally distributed with a mean equal to 20,000 words in excess of that specified in the authorss contract and a standard deviation of 10,000 words. If the publisher wants to be almost certain (say with a probability of .95) that the manuscript will be less than 100,000 words, what number of words should the publisher specify in the contract?

(can you also explain how you got the answer)