Answer:
$13.85
Step-by-step explanation:
If the textbook decreases by 11% per year, this means it will be 89% of the previous year's value since 100% - 11% = 89%
89% in decimal form = 89/100 = 0.89
Therefore, the exponential function is:
[tex]y = 63 \cdot 0.89^x[/tex], where [tex]x[/tex] is the number of years
So when [tex]x=13[/tex],
[tex]y = 63 \cdot 0.89^{13}=13.84875..=13.85[/tex]
