It's Charles and Virginia's 50th anniversary and their children are planning a
celebration. They have a budget of $850. The hall costs $100 to rent and $15
per person. How many people can the children invite?

Monitors manufactured by tsi electronics have life spans that have a normal distribution with a standard deviation of 1800 hours and a mean life span of 20,000 hours. if a monitor is selected at random, find the probability that the life span of the monitor will be more than 17,659 hours. round your answer to four decimal places.