There are 1 0 cards, labeled from 1 to 1 0 , lying face down on a table. You pick a card, and if that card is a 1 0 , you win $ 2 0 . If the card is not 1 0 you win $ 0 . What is the expected amount you would win (in dollars)?
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What you are using here is not linearity of expectation, it is just using the definition of expectation. Linearity of expectation is used when you are taking the expectation of a sum of random variables. You can refer to the expected value technique trainer for a longer explanation of expectation and linearity of expectation.
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Oh, oops, sorry about that. And thanks for the link!
there are only two possible answers 0 $ and 20$ . So how come the concept of probabilty is being used . This is really absurd and futile .
I thought the answer would be which ever amount you had a higher chance of getting...
There are 1 0 cards , so the probability to get number 1 0 card is 1 0 1
because it just 1 card from 1 0 cards
cause the probability to get number 1 0 is 1 0 1
so the expected amount is 1 0 1 × 2 0 dollars = 2 dollars.
On average, if you pick up the cards 10 times, you'll win $20 once. In 10 tries you get $20, so on average you'd win $2 "per try".
Simple way of doing it!
total sum=20 the ways can be attained=10 so 20/10=2
Please elaborate......... I didn't fully understand
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see....there is only single way in which sum can be attained 20 and toatl 10 possibilities so 20/10=2.......:)
elaborated it below
Please elaborate..
mathematical expectation is the sum of probabilities multiplied by the rate..... here, p(selecting the card labeled 10) is 1/1o therefore, expectation E= 1/10 * 20 = 2.
In ten tries you are expected to get the "10"card once, winning you 20 dollars 20 divided by 10 equals 2
prob of winning=1/10 and winning amount =20$..we can expect 1/10th of amount which is equal to 2$
You are expected to win $2. this is because you have a 1/10 chance of winning $20 and a 9/10 chance of winning $0. you add the answer to 1/2 X 20 and 9/10 x 0. the answer to this is 2. so the average winning is $2.
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There is a 1 0 1 probability of picking the card labeled 1 0 and winning $ 2 0 . There is a 1 0 9 probability of picking any other card and winning nothing. Thus, by the Linearity of Expectation Value, our answer is $ ( 1 0 9 ⋅ 0 + 1 0 1 ⋅ 2 0 ) = $ 2 .