Final answer:
The amount marked down for a $187.75 item after a 45% discount is $84.49, by converting the percentage to a decimal and then multiplying by the original price.
Step-by-step explanation:
To determine the amount of money marked down if a store owner lowers the cost of an item by a certain percentage, you can use the formula for calculating the percentage decrease. In this case, a $187.75 item is marked down by 45%. First, convert the percentage to a decimal by dividing by 100.
0.45 = 45 / 100
Next, multiply the original price by the decimal to find the amount by which the item is discounted.
$187.75 × 0.45 = $84.4875
Therefore, the item is marked down by $84.49 when applying a standard rounding rule.