Help me please also with this one please

For a function f(x), a) if f(7) = 22 then f^-1(22) = b) f^-1(f(c)) =

The perimeter of a quarter circle is 14.28 miles. what is the quarter circle's radius?

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?