Question

Having trouble with statistics, specifically probability.

Answer 1

is there a specific problem or concept you need explained?

Answer 2

A local video store owner is examining his two stores, the one on 29th Avenue and the other on Division. The 29th store does 70% of the dealer's business and the Division store does the rest. In the Division store, 40% of all rentals are DVDs. In the 29th store, 30% of all rentals are DVDs. If a customer is selected at random, what is the probability that she will rent a DVD?

Answer 3

sorry, it's a question on paper, so I had to type it out.

Answer 4

what are some ideas you have considered?

Answer 5

storeA does 70% of the dealer's business
storeB does the rest.

In B, 40% of all rentals are DVDs.
In A, 30% of all rentals are DVDs.

If a customer is selected at random, what is the probability that she will rent a DVD?

P(storeA and DVD), or P(storeB and DVD)

Answer 6

okay

Answer 7

lets imagine we have 1000 people.

we seperate them into 2 different rooms:

70% in roomA, and 30% in roomB
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we ask the 700 people in roomA if they got a DVD, and 30% of them say yes

we ask the 300 people in roomB if they got a DVD, and 40% of them say yes
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so, out of 1000 people, how many are there altogether that have a DVD?

7*30, and 3*40 .. 210+120 = 330
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330 people out of 1000 have a DVD. so our probability is?