I have created a spreadsheet for aiding me in an automobile purchase.
It computes the invoice, fees, taxes, and monthly payments. Generally,
sales taxes are straight-forward, yet sales tax in my county remains
complex. My County charges 7% on first $5,000 and 6% on the rest. My
spreadsheet has a cell with the sales tax rate, but the sales tax
calculation formula assumes a constant rate. I need some advice on the
best approach on calculating the sales tax and the related formula.
Should I use the MOD function or compute a fixed rate? Please explain
the formula since I am fuzzy on it.