yeah my working for part c is : P(car owner/bike owner) = 0.78 / (0.85+0.3) = 0.678 I know it is wrong and i dont know how i should do it
Look up the formula again. P(car owner AND bike owner) = 78 * 0.3 should be in the numerator.
The denominator is clearly wrong, you can't have a probability of greater than 1.
The probability of being being a bike owner is either being a car owner and a bike owner (0.85 * 0.3) or (+) not a car owner and a bike owner (0.22 * 0.85).
Look up the formula again. P(car owner AND bike owner) = 78 * 0.3 should be in the numerator.
The denominator is clearly wrong, you can't have a probability of greater than 1.
The probability of being being a bike owner is either being a car owner and a bike owner (0.85 * 0.3) or (+) not a car owner and a bike owner (0.22 * 0.85).
Have you drawn a tree diagram...?
yes i have drawn a tree diagram and sorry for the non knowledgeable reply, but i am really bad in stats... My tree diagram is right and after i have read your comment, i think i realised i should have done: 0.78 x 0.3 / 0.78 x 0.3 + 0.22 x 0.85 ?
yes i have drawn a tree diagram and sorry for the non knowledgeable reply, but i am really bad in stats... My tree diagram is right and after i have read your comment, i think i realised i should have done: 0.78 x 0.3 / 0.78 x 0.3 + 0.22 x 0.85 ?
What's the probability of someone being a bike owner? Look at your tree diagram and multiply along the branches and add up the relevant probabilities.
So, what is the probability that the person is not a bike owner? (hint: 1- probability he is a bike owner).
Then the probability that only one person is a bike owner amongst 2 people is:
P(Bike owner)P(not bike owner) + P(not bike owner)P(bike owner).
the probability of a bike owner is 0.78 x 0.3 + 0.22 x 0.85 = 0.421 The probability of not a bike owner is 0.78 x 0.7 + 0.22 x 0.15 = 0.579 So The probability of one person out of two is a bike owner would be: 2(0.421 x 0.579)? the highlighted bit i still dont understand
the probability of a bike owner is 0.78 x 0.3 + 0.22 x 0.85 = 0.421 The probability of not a bike owner is 0.78 x 0.7 + 0.22 x 0.15 = 0.579 So The probability of one person out of two is a bike owner would be: 2(0.421 x 0.579)? the highlighted bit i still dont understand
Did you read my post? What does the last line of my post say?