Answer: $3.51
Explanation:
Given : Kevin buys 4 folding chairs.
Each chair costs $13.50.
The sales tax = 6.5% = 0.065
Cost of 4 folding chairs= 4 x Cost of one chair

Amount of Sales tax = 0.065 x Cost of 4 chairs
=

Hence, the amount of sales tax for Kevin's purchases = $3.51