There is no formula that will tell you the interest rate. It must be computed iteratively or found graphically. A financial calculator can do the work for you.
The parameters this one uses are
number of payments (24)
the amount financed (1925 -125 = 1800)
the monthly payment, negative because it is being paid (-88.00)
the remaining balance after all payments (0)
the number of payments per year (monthly = 12)
the number of times per year interest is compounded (monthly = 12)