For each student, there are only two possible outcomes. Either they own a wireless device, or they do not. The probability of a student owning a wireless device is independent from other students. So we use the binomial probability distribution 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.

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

In which $C_{n,x}$ is the number of different combinations of x objects from a set of n elements, given by the following formula.

$C_{n,x} = \frac{n!}{x!(n-x)!}$

And p is the probability of X happening.

81% of students own a wireless device.

This means that $p = 0.81$

If 5 students are selected at random, what is the probability that all 5 have a wireless device?

This is P(X = 5) when n = 5. So

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 5) = C_{5,5}.(0.81)^{5}.(0.19)^{0} = 0.3487$

34.87% probability that all 5 have a wireless device

5 0

3 years ago

The endpoints of a segment are (10, 0) and (20, 0) how do you know it is a horizontal segment

Tju [1.3M]

You can see it easily if you graph A(10,0) & B(20,0) on a on a system of perpendicular axis. The horizontal values (x value =10 & 20) are on the x axis & the vertical values (y value=0 & 0) can't be on the y axis since y values are zero

8 0

3 years ago

What is 5 13/15 rounded to the nearest integer

Charra [1.4K]

Answer:

Step-by-step explanation:

5 * 13/15 ≈ 4,33 ≈ 4

3 0

3 years ago

Read 2 more answers

Only answer if you are 100% sure about the answer.

hram777 [196]