Sally’s aunt put money in a savings account for her on the day Sally was born. The savings account pays interest for keeping her money in the bank. After one year, the interest had accumulated, and the total was $312 in Sally’s account. After three years, the total was $340. After six years, the total was $380. After nine years, the total was $430. Hint: x is the number of years, y is the value of money in the account

Nonportional or proportional