Answer:
$6
Explanation:
Round $42.58 to the nearest ten dollars to get $40. $40 ÷ 100 = $0.4 so this is one percent. $0.4 × 15 is $6 which is an estimate of 15% of $42.58.
The answer is $6 (unless if you are meant to add this to $42.58 - then the answer would be $48.58 - but I am not sure because of the wording of the question).