The cost price for the shirt is $7
CP = $7
Mark up = 350%
The mark up is given by the formula:
Profit = Selling Price - Cost Price
Profit = 9.5 - 7
Store's Profit = $2.5
Tax % = 8.5%
Tax = 8.5% of the cost price
Tax = (8.5/100) x 7
Tax = 0.085 x 7
Tax = $0.595
Total = Tax + Cost Price
Total = $0.595 + $7
Total = $7.595