Answer:
The percent change in price is 400% 
Step-by-step explanation:
Given, the ticket was $4.00 in 1999 
And $ 20.00 in 2009 
Let, price for 1999 be P1 = $4 
Price for 2009 be P2 = $20 
Percent change in price is calculated by the formula, 

Substituting the values in the formula, 

% change = 16/4 * 100 = 400% 
Therefore, the percent change in price is 400%