In 2013 Skittles changed the flavor of green from lime to sour apple (big mistake!!). Mrs. Rowland takes a small handful of 5 Skittles from a bin of 10,000 Skittles and gets ALL GREEN (terrible)! If 20% of the Skittles are green, what is the probability of this happening

Respuesta :

Answer:

0.032% probability of this happening

Step-by-step explanation:

Since the distribution is very large(10,000 skittles), and there are only two possible outcomes(either the Skittles is green or it is not) we can use the binomial probability distribution as an approximation.

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 combinations 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 p is the probability of X happening.

Handful of 5 skittles:

This means that [tex]n = 5[/tex]

20% of the Skittles are green

This means that [tex]p = 0.2[/tex]

What is the probability of this happening?

Probability of all skittles being green, so [tex]P(X = 5)[/tex].

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

[tex]P(X = 5) = C_{5,5}.(0.2)^{5}.(0.8)^{0} = 0.00032[/tex]

0.032% probability of this happening