An airline has 81% of its flights depart on schedule. It has 69% of its flights depart and arrive on schedule. Find the probability that a flight that departs on schedule also arrives on schedule.

1.25
0.85
0.45
0.43

Question

An airline has 81% of its flights depart on schedule. It has 69% of its flights depart and arrive on schedule. Find the probability that a flight that departs on schedule also arrives on schedule.

1.25
0.85
0.45
0.43

anonymous · Answer

probablity=desired divided by total
 
I don't know if this could help?

anonymous · Answer

uhh Idk, I need the steps :P @Mertsj help please?

anonymous · Answer

isnt that the 69%?

anonymous · Answer

what do you mean?

anonymous · Answer

well it says 69% departs and arrives on time and then the question asks the probability of flights that depart and land on schedule

anonymous · Answer

so wouldnt you do 69 divided by 81?

anonymous · Answer

Ummmmmm... I wish I knew, I guess that could be right ? :P Do you know for sure that's what to do?

anonymous · Answer

Sorry, i'm just terrible at statistics :P

mertsj · Answer

A = departs on schedule
P(A)=0.81
B = arrives on schedule

P(A and B) = 0.69
P(B/A) = P( A and B) / P(A) = 0.69/0.81 = 0.85

anonymous · Answer

yeah thats what you do...because it is giving you the starting percent of 81 being on time...out of that 69 has both so you would divide 69/81

anonymous · Answer

Ohhh, thanks soo much guys, I would give medal to both but I'll give to Hope since she needs more :)

anonymous · Answer

well thanks :D

mertsj · Answer

Me too.

anonymous · Answer

awh you guys are awesome :D