Question

assume that when adults with smartphones are randomly selected 58% use them in meetings or classes if nine adults smartphone users are randomly selected find the probability that exactly three of them use their smartphones and meetings or classes

Answer 1

Assume that when adults with smartphones are randomly selected 58% use them in meetings or classes

If nine adult smartphone users are randomly selected find the probability that exactly three of them use their smartphones and meetings or classes​.

The problem can be solved using the binomial distribution

$P\mleft(x\mright)=^nC_x\cdot p^x\cdot(1-p)^{n-x}$

Where n is the number of trials, x is the variable of interest and p is the probability of success.

p = 0.58

n = 9

x = 3

Let us substitute the given values into the above formula

$\begin{gathered} P(x=3)=^9C_3\cdot(0.58)^3\cdot(1-0.58)^{9-3} \\ P(x=3)=84\cdot(0.58)^3\cdot(0.42)^6 \\ P(x=3)=0.0900 \\ P(x=3)=9.00\% \end{gathered}$

Therefore, there is a 9.00% probability that exactly three of them use their smartphones and meetings or classes​.