Final answer:
To calculate the original purchase price of the stock, divide the selling price of $176.64 by 1.15, because the selling price includes the 15% profit. This gives an original purchase price of $153.60 per share.
Step-by-step explanation:
If Warren sold his stock at a 15% profit and the selling price was $176.64 per share, we need to find out the original purchase price per share. The selling price represents 115% of the original price (100% + 15% profit). Therefore, to find the original price, we can set up the equation:
115% of original price = $176.64
We convert 115% to a decimal by dividing by 100, which gives us 1.15:
1.15 × (original price) = $176.64
To find the original price, we divide the selling price by 1.15:
Original price = $176.64 / 1.15
Original price = $153.60 per share
Thus, Warren bought the stock for $153.60 per share before selling it for $176.64 per share, realizing a profit.