Statistics Question

[匿名]

2010-09-03 2:27 am

There are 2 types of lottery tickets in the city, namely A and B.
Scheme of A : One 1st prize $5000 and three 2nd prize $500 each.
Scheme of B : One 1st prize $n, two 2nd prize $3000 each and five 3rd prize $1300 each.
Price of ticket of lottery B is twice that of lottery A.
If the expected amount won per dollar paid for A and B is the same, find value of n?

更新1:

Sorry, some information was missing : There are 400 tickets sold under lottery A and 1000 tickets sold under lottery B. Sorry.

更新2:

To : Stevie - G. Your answer is wrong, sorry. Answer is independent of x.

更新3:

To : Stevie-G: Answer of $20,000 is correct, but why expected winning money does not include x and 2x? These are the cost of buying the tickets. Can you explain?

回答 (1)

STEVIE-G™

2010-09-03 3:11 am

✔ 最佳答案

As follows:

圖片參考：http://i707.photobucket.com/albums/ww74/stevieg90/05-78.jpg

2010-09-02 19:43:19 補充：
The updated sol. is posted...Tell me if my ans is wrong...

2010-09-02 23:18:19 補充：
Yes...I've updated the sol. The answer is n=20000, is it correct?

2010-09-03 12:26:01 補充：
If you are asked to calculate "Expected Value", then:
for A, the expected value=65/4-(396/400)*(-x)
for B, the expected value=(n+12500)/1000-(992/1000)*(-2x)

However, you are asked to calculate "Expected Winning Money", so we should consider only the possible winning events.

參考: http://i707.photobucket.com/albums/ww74/stevieg90/05-78.jpg

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