This question can be solved by:

Cross multiply to get: 8.3x = 3,560,000
To let the x stand along (since you are finding the x value), divide 8.3 to both sides of the equal sign.

Simplify to get the answer.
Answer:
25%
Step-by-step explanation:
Since we know that the markdown is $20 by subtracting 80-60 , we find out what percent of 20 is 80. To do that you do 20/80, which is 0.25, or 25 percent.
Relative frequency = (number of times an item appears) /(TOTAL numbers)
Relative frequency (selecting Red ) = 13/30 =0.434