(5) Use a (logically chosen) linear approximation of f(x, y) = p x + y 3 to estimate √ 1.02 + 1.993 . Use a calculator to compute √ 1.02 + 1.993 and compare the result to the approximation. (The approximation better be pretty close to the calculator value!)

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?