It is given that the price of the box increases from R17.99 to R19.99.
It is required to find the inflation rate for the period.
Recall the formula for the Inflation Rate:
[tex]\frac{\text{ Current price}-\text{ Initial price}}{\text{ Initial price}}\times100\%[/tex]
Substitute the given prices:
[tex]\frac{19.99-17.99}{17.99}\times100\%=\frac{2}{17.99}\times100\%=\frac{200}{17.99}\%\approx11.1\%[/tex]
The answer is about 11.1%.
