Here are some typical loan scenarios:
$120 Loan
$120.00 @ 3.50% APR x 137 Days
(May 16 through Sep. 30) $1.58 Interest
$121.58 Total
$200 Loan
$200.00 @ 3.50% APR x 168 Days
(Apr. 15 through Sep. 30) $3.22 Interest
$203.22 Total
$1,200 Loan
$1,200 @ 3.50% APR x 288 Days
(Dec. 16 through Sep. 30) $33.14 Interest
$1,233.14 Total