## anonymous one year ago I need this one answer. The Venn Diagram shows the number of bike and skate club members who bike (circle on the left) or skate (circle on the right). Compute P (S | B) and write your answer as a decimal. P (S | B) = a0 ways.

1. anonymous
2. misty1212

HI!!

3. misty1212

make a fraction in the top, put then number of things in the intersection in the bottom, but the number of things iB

4. anonymous

I got 6 as my answer is that right?

5. misty1212

heck no!!

6. misty1212

lets go slow

7. misty1212

first, you are asked for a probability the answer must be a number between 0 and 1, it cannot be 6

8. misty1212

i actually don't see a 6 anywhere in the diagram but no matter what is the number in the intersection of that diagram (the number in both circles)?

9. anonymous

0.17 or 0.16?

10. anonymous

yeah lets take it slow then lol

11. misty1212

what is the number in the intersection?

12. misty1212

|dw:1435064802651:dw|

13. anonymous

5

14. misty1212

right there are 5 things in $$B\cap S$$ meaning i guess 5 people both bike and skate that will be the numerator of the fraction (the top)

15. misty1212

now what is the total number in B (the total, not just the 20)?

16. misty1212

really? what two numbers do you see in B?

17. misty1212

B = Bike on the left

18. anonymous

oh 20 is what i see

19. misty1212

yes, but that is not ALL that is in B

20. anonymous

and 5 as well?

21. misty1212

the 20 is outside of the intersection you have to include the intersection as well

22. misty1212

right for a total of ?

23. anonymous

25

24. misty1212

right

25. misty1212

now we can compute the answer

26. anonymous

alright how so

27. misty1212

$P(S|B)$means the probability that you skate GIVEN that you bike there are 25 people who bike of those 5 also skate

28. misty1212

make a fraction, put the 5 in the numerator and the 25 in the denominator

29. anonymous

i got 0.2

30. misty1212

ok that looks good since $\frac{5}{25}=\frac{1}{5}=0.2$

31. anonymous

alright so 0.2 is the answer then correct?

32. misty1212

i have a feeling you did not really understand what was going on go back and look at what we did, convince yourself that a) it makes sense and b) it is not that hard yeah 0.2

33. anonymous

Thank you and sorry im not very good with this problems lol

34. misty1212

no need to apologize, it is not like you are born knowing it, but it is understandable