Asked by Looking for someone to check my answer

I don't know where to start with this one. What is the formula and how do I go about answering this?

Question:
If one of the 255 subjects is randomly chosen, what is the probability that the person prefers orange juice, given they are over 40? Round your answer to 3 decimal places.

Water Orange Cola
juice
Under 21 years 40 25 20
21 – 40 years 35 20 30
Over 40 years 20 30 35

Answered by PsyDAG
Assuming the central vertical value is OJ, 30/255.
Answered by PsyDAG
There was no answer to check.