What annual rate of interest was earned if a $19,000 investment for five months earned $708.55 in interest?

$708.55 interest is for 5 months. If we want to know the amount of interest for 12 months or for full year then we will proportionate the amount as follows :

Amount of interest for a year = 708.55 × 12 /5 = $1700.52

Rate of interest = Amount of interest for a year × 100 / Amount of investment

1700.52 × 100 / 19,000 = 8.95%

So answer is 8.95 %