ANSWER
995%
Step-by-step explanation
When they opened their shakes cost $0.20 and now they cost $2.19.
To find the percent of change, we have to first find the difference in the initial cost and the current (or final) cost and then divide that by the initial cost, then multiply by 100 (per cent).
Initial Cost = $0.20
Final Cost = $2.19
Difference = Final - Initial = 2.19 - 0.20
Difference = $1.99
The percent of change is: