You are a newsvendor selling San Pedro Times every morning. Before you get to work, you go to the printer and buy the day's paper for $0.25 a copy. You sell a copy of San Pedro Times for $1.25. Daily demand is distributed normally with mean = 255 and standard deviation = 51. At the end of each morning, any leftover copies are worthless and they go to a recycle bin.

a. How many copies of San Pedro Times should you buy each morning? (Use Excel's NORMSINV() function to find the correct critical value for the given -level. Round your z-value to 2 decimal places and final answer to to 2 decimal places.)

b. Based on a, what is the probability that you will run out of stock? (Round your answer to the nearest whole number.)