Alot is 21 ft by 30 ft. to support a fence, an architect wants an upright post at each corner and an upright post every 3 ft in between. how many of these posts are needed?

The weekly amount spent by a company for travel has an approximately normal distribution with mean = $550 and standard deviation = $40. a) what is the probability that the actual weekly expense will exceed $570 for more than 20 weeks during the next year? (note: one year = 52 weeks) b) what is the probability that actual weekly expenses exceed $580 for 10 or more, but 16 or fewer weeks during the next year?