What is the minimum tax that pedro should pay to make the tax structure vertically equitable with respect to the amount of tax paid?

The complete question would be:

Given the following tax structure,

Taxpayer Salary Total Tax

Mae $13,300 $1,755.60

Pedro $33,500?

Venita $23,750?

What is the minimum tax that Pedro should pay to make the tax structure vertically equitable based on the tax rate paid?

Minimum tax of $ 4,422.00