Answer:
The second one
Step-by-step explanation:
I believe this because congruent means same in she and SIZE and the second one is not the same is size
 
        
             
        
        
        
Amy:
8 + 5 + 6 + 11 + 4 + 6 +8 = 48
48 divide by 7 = 6.85
chelsea: 
7 + 9 + 5 + 3 + 10 + 5 + 8 = 47
47 divide by 7 = 6.71
amy runs more on average.
both mean !
        
                    
             
        
        
        
Answer:
The expression for the average number of tickets sold per school child is:

Step-by-step explanation:
The average number of tickets sold per school child is the weighted mean calculus between the number of tickets sold by these classes and the number of children in each classes.
This is the multiplication between the number of tickets sold by these classes and the number of children in each classes divided by the total weight(in this exercise, the total weight is the total number of school child).
So, the expression for the average number of tickets sold per school child is:

 
        
             
        
        
        
A^2 + b^2 = c^2
5^2 + b^2 = 20^2
25 + b^2 = 400
b^2 = 375
b = 19.4 feet