Final answer:
To find the new price of the less popular book, the percentage increase of the popular book was calculated, which was approximately 6.98%. This percentage was then used to decrease the original price of the less popular book ($18.75) to find the new price, which is $17.44.
Step-by-step explanation:
The question asks how to find the new price of a less popular book after it has been reduced by the same percentage as the increase in the price of a popular book. To solve this, we first calculate the percentage increase in the popular book's price. The price went from $11.75 to $12.57, an increase of $12.57 - $11.75 = $0.82. The percentage increase is $0.82 / $11.75, which is approximately 6.98%.
The less popular book originally cost $18.75. To find the reduced price, we decrease it by the same percentage. Thus, the decrease amount is 6.98% of $18.75, which is $18.75 * 0.0698 = $1.3085. The new price is $18.75 - $1.3085 = $17.4415, which, when rounded to the nearest cent is $17.44. So, the new price of the less popular book is $17.44, making the correct answer D.