$15)$ Wiley$$s Wilderness pays $6$ percent interest on its outstanding debt, which equals $$200,000.$ The company$$s sales are $$540,000,$ its tax rate is $40$ percent, and its net profit margin is $4$ percent. $($a$)$ What is Wiley$$s TIE? $($b$)$ If Wiley$$s wants to maintain the TIE equal to $6\mathrm{.}0,$ what must its sales equal?