A puppy named Bruno started out at 4 pounds and gained 1 pound every month. At how many months did Bruno weigh 10 pounds?

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.