Answer:
negative $1.60 was the "interest" added to Vito's account
Step-by-step explanation:
new balance = old balance + deposits - withdrawals + interest
$9669.26 = $6955.01 + 2815.85 - 100.00 + interest . . . . fill in givens
$9669.26 = $9670.86 + interest . . . . . simplify
$9669.26 - 9670.86 = interest = -$1.60 . . . . . subtract 9670.86
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Comment on the problem
This result is "unexpected." Usually an interest amount will be positive. Please have your teacher work this problem for you and explain the result.