Given:
Cost of computer=$115.00
Sales tax=$8.05
The objective is to find the sales tax rate.
The formula for sales tax rate is,
[tex]\begin{gathered} \text{Sales tax=Item cost}\times Sales\text{ tax rate} \\ Sales\text{ tax rate}=\frac{Sales\text{ tax}}{Item\text{ cost}} \\ Sales\text{ tax rate}=\frac{8.05}{115} \\ Sales\text{ tax rate}=0.07 \\ Sales\text{ tax rate}=7\text{ percentage.} \end{gathered}[/tex]