A pizza restaurant has found that the probability that a customer will order thin crust is 0.4. In a random sample of 5 customers who order a pizza, find the probability that at least three of them want thin crust.

Respuesta :

In this type of exercises, the probability of x successes on n reapeted trials in an experiment is given by the next formula:

[tex]P=\text{nCx}\cdot p^x\cdot(1-p)^{n-x}[/tex]

Here the nCx indicates the number of different combinations of x objects selected from a set of n objects. With the given data we can solve it easily:

p = 0.4

n = 5

x = 3

[tex]\begin{gathered} P=5\text{C3}\cdot0.4^3\cdot(1-0.4)^{5-3} \\ P=10\cdot0.064\cdot0.36 \\ P=0.2304 \end{gathered}[/tex]