Note: Since i could not copy the text of the question i had to attach it as images.
I have 1 question in my book as below Data Question
The correct answer to this question is 108.7% based on the reasoning explained in the book; it made sense. They have mentioned that If A is the dollar amount in 2007 for Store T, thus in 2008 the dollar amount will be 0.92A. Thus 1/0.92 = 1.0869 = 108.7%
I tried below approach (the answer was wrong) and i wish to understand the gap in my understanding.
% change from 2006-2007 is 17% --> 117% % change from 2007-2008 is -8% --> 109% So (117/109)*100 --> 107.339%
A drop of $8\%$ of $117\%$ from $117\%$ is $-9.36\% = 107.64\%$.
$$\frac{117}{107.64}\cdot 100 = 108.7\%$$