Answer:
Percentage change = 26.61 % 
Explanation:
Given
To determin
Percentage change = ?
Using the formula
Percentage change = (Final value - Initial value) / | Initial Vaue | × 100%
 = (100 - 78.98) / 78.98 × 100%
 = [21.02/78.98] × 100%
 = 0.266143 × 100%
 = 26.6143 % 
Rounding off to 2 decimal places 
 = 26.61 %
Therefore, 
Percentage change = 26.61 %