Answer
Answer: $661.5
Work Step by Step
Cost of Item = 630 Dollar
Tax rate = 5%
As we know, Amount of tax = Tax rate $\times$ Cost of Item
i.e. Tax = 5%$\times $630 = 0.05 $\times$ 630 = 31.5
Total Cost = Cost of Item + Tax = 630 + 31.5 = 661.5 Dollars