Answer-
The total cost of his purchase will be $3,846.34
Solution-
Here, the annual interest rate is 17.45%.
So monthly interest rate will be,

With a purchase of $3,740, the amount will be after one month,

Then she makes a payment of $1350, so the balance at the end of month 1 is

Now she has to pay with $2444.37 as principal amount, the amount will be after one month,

Then she again makes a payment of $1350, so the balance at the end of month 2 is
Final month, she has to pay with $1129.91 as principal amount, the amount will be,

So the total cost, including interest, would be the sum of the three payments,
