175k views
1 vote
Assume that when adults with smartphones are randomly​ selected, 46​% use them in meetings or classes. If 9 adult smartphone users are randomly​ selected, find the probability that exactly 3 of them use their smartphones in meetings or classes.

User Yordanka
by
7.9k points

1 Answer

5 votes

Answer:

0.2027 is the probability that exactly 3 out of 9 adults use their smartphones in meetings or classes.

Explanation:

We are given the following information:

We treat adult using smartphones in meetings or classes as a success.

P(Adult using smartphone) = 46% = 0.46

Then the number of adults follows a binomial distribution, where


P(X=x) = \binom{n}{x}.p^x.(1-p)^(n-x)

where n is the total number of observations, x is the number of success, p is the probability of success.

Now, we are given n = 9

We have to evaluate:


P(x = 3)\\\\= \binom{9}{3}(0.46)^3(1-0.46)^6\\\\= 0.2027

0.2027 is the probability that exactly 3 out of 9 adults use their smartphones in meetings or classes.

User Leosz
by
8.8k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories