Answer:
10.53%
Step-by-step explanation:
Percentage change can be found using the formula ...
percent change = ((new value) - (old value))/(old value) × 100%
For your numbers, this is ...
percent change = (($21 -$19)/$19) × 100% = 2/19×100% ≈ 10.53%
The increase is about 10.53%.
