Question

Anyone any good at probability? I just need to know if this problem is an independent addition or something else.
If 2000 people walked into a building and 430 of them are males. Estimate the probability the next one is well be a male... Never had a question like this before and I am stuck

Answer 1

63%

Answer 2

Probably looking to use Bayes' Theorem here. P(A|B)=P(B|A)P(A)/P(B)

Answer 3

We don't cover Bayes Theorem at my level

Answer 4

In that case they may just be looking for the answer 50%, but if so it's a poor problem.

Answer 5

P(male) = 430/2000

Answer 6

I am thinking maybe P(A and B) 430/2000(1/2000) but i don't know if I even wrote that right, I know it is indep, because who walked into the building last doesn't effect the sex and who walks in next

Answer 7

Consider a person walking through the door as a trial of gender. There were 2000 trials and if the occurrence of a male is considered a success, there were 430 successes. The number of trials is large (2000) Therefore the probability that the next person who walks through the door will be male is 430/2000.

Answer 8

That almost seems too simple, I like to make things harder LOL

Answer 9

Well I don't think it was very simple. Most of the arithmetic in stats appears simple (bearing in mind that much of the heavy stuff is in tables) but knowing and correctly using the main theorems takes effort.

Answer 10

Yes, and thats where I am struggling

Answer 11

My approach has been to do plenty of examples and make sure you get them all correct (that means getting help sometimes). Good luck with your studies :)