Probability Problems

MathStudent1999

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4. Two baseball teams which are evenly matched play a series of games in which the first team to win four games is declared the winner of the series. What is the probability that they will have to play seven games before the series is decided, assuming that each team has a 50-50 change of winning the each game? Express your answer as a common fraction.

16. Ian uses a weighed coin to decide whether to move north or east. If the coin comes up head, he moves north and if the coin comes up tails, he moves east. Ian discovers after many random walks that he is sixteen times more likely to end up 3 blocks north and 1 block east than he is to end up 1 block north and 3 block east after 4 coin tosses. What is the probability that the coin show up heads? Put you answer as a common fraction.

Please help me on these two questions
 

MathStudent1999

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Can someone give me a few hint and tips on these questions?
 

Subhotosh Khan

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4. Two baseball teams which are evenly matched play a series of games in which the first team to win four games is declared the winner of the series. What is the probability that they will have to play seven games before the series is decided, assuming that each team has a 50-50 change of winning the each game? Express your answer as a common fraction.

16. Ian uses a weighed coin to decide whether to move north or east. If the coin comes up head, he moves north and if the coin comes up tails, he moves east. Ian discovers after many random walks that he is sixteen times more likely to end up 3 blocks north and 1 block east than he is to end up 1 block north and 3 block east after 4 coin tosses. What is the probability that the coin show up heads? Put you answer as a common fraction.

Please help me on these two questions
Trying different web-sites to get somebody to do your homework - without doing a single line of work - is frowned upon here.

Duplicate Post:

http://mathhelpforum.com/statistics/196119-probability-problem.html
 

MathStudent1999

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MathStudent1999

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Please Help :(
 

HallsofIvy

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In order that a series end in 4 games, one team must win four consecutive games. What is the probability of that?

In order that a series end in 5 games, one team must win four games and the other 2. What is the probability of that?

In order that a series end in 6 games, one team must win four games and the other 3. What is the proability of that?

Each of those requires a binomial distribution calculation. The sum is the probability that the series end in less than seven games and the probability that the series requires 7 games is 1 minus that number.
 

HallsofIvy

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In order that a series end in 4 games, one team must win four consecutive games. What is the probability of that? In order that a series end in 5 games, one team must win four games and the other 2. What is the probability of that? In order that a series end in 6 games, one team must win four games and the other 3. What is the proability of that? Each of those requires a binomial distribution calculation.  The sum is the probability that the series end in less than seven games and the probability that the series requires 7 games is 1 minus that number.
 

MathStudent1999

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In order that a series end in 4 games, one team must win four consecutive games. What is the probability of that?

In order that a series end in 5 games, one team must win four games and the other 2. What is the probability of that?

In order that a series end in 6 games, one team must win four games and the other 3. What is the proability of that?

Each of those requires a binomial distribution calculation. The sum is the probability that the series end in less than seven games and the probability that the series requires 7 games is 1 minus that number.
Is the correct answer 5/16?
 
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