Answer:

Step-by-step explanation:
Donna's Rate is 
Rico's Rate is 

Cross-Multiply



Donna's Rate is 
Rico's Rate is 

x=96
all interior angles equal 180
Subtract exterior andgles by 180 to get interior angles because they are supplementary
180-134=46
180-130=50
Get the third angle inside the triangle
180-50-46=84
subtract by 180 to get x because they are supplementary
180-84=96
Therefore x =96
Correlated means that they relate so probably this might help
The top 4 firms have (23 +22 +18 +12)% = 75% of the market.
The 4-firm concentration ratio is 0.75 or 75%.