For this case, the first thing we must do is find the amount of taxes.
For this, we make the following rule of three:
89.75 ----------------------> 100%
x ----------------------------> 7 1/4%
From here, we clear the value of x.
We have then:

Then, the total cost is given by:

Substituting values:

Answer:
The total cost is equal to 96.26 $.