I'm not too sure what I'm doing wrong? Is there anyway someone could help walk me through this problem.

A statistics professor has noted from past experience mat a student who follows a program of studying two hours for each hour in class has a probability of 0.8 of getting a grade of C or better, while a student who does not follow a regular study program has a probability of 0.3 of getting a C or better. It is known that }'0% ofie students follow the study program. Find the probability that a student who has earned a C or a better grade followed the program. (Round your answer to four decimal places.) 3: Need Help