SOLUTION
Step1: Write out the giving parameters
[tex]\begin{gathered} \text{sales tax=\$43} \\ \text{Purchasing value=\$860} \end{gathered}[/tex]Step2: Write out the formula
[tex]\text{sales tax rate =}\frac{sales\text{tax}}{purcha\sin g\text{ value}}\text{ }[/tex]Step3: Substitute the parameter into the formula
[tex]\text{sales tax rate=}\frac{43}{860}=\frac{1}{20}[/tex]Then in percentage, the sales tax rate becomes
[tex]\frac{1}{20}\times100=5\text{ \%}[/tex]Therefore the sales tax rate is 5 %