Answer
Answer:
Tax Rate = 7.5 %
Total Cost = $838.5
Work Step by Step
Cost of Item = 780 Dollar
Amount of Tax rate = 58.50 Dollar
Amount of tax = Tax rate $\times$ Cost of Item
i.e. 58.50 = Tax rate$\times $780
Tax rate= 58.5 $\div$ 780 = 0.075
So, Tax rate = 7.5%
Total Cost = Cost of Item + Tax = 780 + 58.50 = 838.5 Dollars