SOLUTION: Why isn't spinning a roulette wheel 4 times, keeping track of the winning >numbers a binomial of distribution? > > A test consists of 10 true/false questions. To pass the test

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Question 350677: Why isn't spinning a roulette wheel 4 times, keeping track of the winning
>numbers a binomial of distribution?
>
> A test consists of 10 true/false questions. To pass the test a student must
> answer at least 7 questions correctly. If a student guesses on each
> question, what is the probability that the student will pass the test?
>
> A study conducted at a certain college shows that 75% of the school's
> graduates find a job in their chosen field within a year after graduation.
> Find the probability that 8 randomly selected graduates all find jobs in
> their chosen field within a year of graduating.
>
> You are dealt two cards successively (w/o replacement) from a shuffled deck
> of 52 playing cards. Find the probability that both cards are black.
>
> Find the standard deviation if x=0 and P(X)=.15, x=1 and P(X)=.33, x=2 and
> P(x)=.05, x=3 and P(x)=.19, x=4 and P(x)=.28
>
> Thank you and if you could show me how you worked the problems out that
> would be very helpful!
>

Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!

>Why isn't spinning a roulette wheel 4 times, keeping track of the winning
>numbers a binomial of distribution?
.
.
Binomial distributions only work when two choices are available, heads or tails on a coin, True or False on a test. A roulette wheel has multiple numbers (more than 2), 3 colors (red, black, and green) so could not be modeled as a binomial distribution.
.
.
.
> You are dealt two cards successively (w/o replacement) from a shuffled deck
> of 52 playing cards. Find the probability that both cards are black.
.
.
.
P%28B%29=26%2F52=1%2F2
Once a black card is dealt, the total number of black cards and total cards reduces by 1. Then
P%28B%29=25%2F51
So then to get the probability of drawing two black cards in a row, multiply the individual probabilities together.
P%282B%29=%281%2F2%29%2825%2F51%29=25%2F102