I bought a 2020 forte . I traded my 2015 in on it ...

I bought a 2020 forte . I traded my 2015 in on it . I would like to know how my payments go up from 307.00 to 450.00 how do they get that. My car was only 5 yrs different, low miles it only had 38,000 miles on it and . How do they work the numbers.