For each of the following binomial random variables, specify n and p. (a) A fair die is rolled 50 times. X = number of times a 5 is rolled. n = 50 Correct: Your answer is correct. p = 1/5 Incorrect: Your answer is incorrect. (b) A company puts a game card in each box of cereal and 1/100 of them are winners. You buy sixteen boxes of cereal, and X = number of times you win. n = 16 Correct: Your answer is correct. p = 1/100 Correct: Your answer is correct. (c) Jack likes to play computer solitaire and wins about 25% of the time. X = number of games he wins out of his next 26 games.μ =

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Answer:

a) [tex]n = 50, p = \frac{1}{6}[/tex]

b) [tex]n = 16, p = \frac{1}{100}[/tex]

c) [tex]n = 26, p = 0.25, \mu = 6.5[/tex]

Step-by-step explanation:

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

In which [tex]C_{n,x}[/tex] is the number of different combinatios of x objects from a set of n elements, given by the following formula.

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

And [tex]p[/tex] is the probability of X happening.

(a) A fair die is rolled 50 times. X = number of times a 5 is rolled

The die is rolled 50 times, so [tex]n = 50[/tex].

Each roll can have 6 outcomes. So the probability that 5 is rolled is [tex]p = \frac{1}{6}[/tex]

(b) A company puts a game card in each box of cereal and 1/100 of them are winners. You buy sixteen boxes of cereal, and X = number of times you win.

You buy 16 boxes of cereal, so [tex]n = 16[/tex].

1 of 100 are winners. So [tex]p = \frac{1}{100}[/tex].

(c) Jack likes to play computer solitaire and wins about 25% of the time. X = number of games he wins out of his next 26 games.

He plays 26 games, so [tex]n = 26[/tex].

He wins 25% of the time, so [tex]p = 0.25[/tex]

We have that [tex]\mu = np[/tex]. So [tex]\mu = 26*0.25 = 6.5[/tex]