Respuesta :
Answer:
A. Bin(40,0.65)
Step-by-step explanation:
For each adult, there are only two possible outcomes. Either they have a cell phone, or they do not. The probability of an adult having a cell phone is independent of any other adult having a cell phone. This means that the binomial probability distribution is used to solve this question.
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.
In function of its parameters, the distribution is written as: Bin(n,p).
The proportion of adults who own a cell phone in a certain Canadian city is believed to be 65%
This means that [tex]p = 0.65[/tex]
Forty adults are to be selected at random from the city.
This means that [tex]n = 40[/tex].
Thus, we have Bin(40,0.65), and the correct answer is given by option A.
