Assume that when adults with smartphones are randomly selected,

54%

use them in meetings or classes. If

5

adult smartphone users are randomly selected, find the probability that exactly

3

of them use their smartphones in meetings or classes.

2022-04-30
Answered

Assume that when adults with smartphones are randomly selected,

54%

use them in meetings or classes. If

5

adult smartphone users are randomly selected, find the probability that exactly

3

of them use their smartphones in meetings or classes.

You can still ask an expert for help

star233

Answered 2022-05-14
Author has **137** answers

$P\left(\mathrm{Smartphones}\right)=0.54$

$n=5$

$P(x=k)={}^{n}{C}_{k}{P}^{k}{(1-P)}^{n-k};k=0,1,2,...n$

$P(x=3)={}^{5}{C}_{3}{(0.54)}^{3}{(0.46)}^{2}$

$=10{(0.54)}^{3}{(0.46)}^{2}$

=$10\times 0.1575\times 0.2116$

$=0.3333$

asked 2022-04-24

Perform the indicated operation with complex numbers. (Simplify your answe completely.)

$(4-8i)(9+7i)$

asked 2022-04-25

How to solve $\mathbf{\text{x}}\text{'}\text{'}\left(t\right)=\left[\begin{array}{cc}-1& 0\\ 0& -1\end{array}\right]\mathbf{\text{x}}\left(t\right)$

What I'm thinking is to consider the first order version

$\mathbf{\text{x}}\text{'}\left(t\right)=\left[\begin{array}{cc}-1& 0\\ 0& -1\end{array}\right]\mathbf{\text{x}}\left(t\right)$

which I know how to solve, the solution is

$\mathbf{\text{x}}\left(t\right)=\mathbf{\text{c}}\left[\begin{array}{c}{e}^{-t}\\ {e}^{-t}\end{array}\right]$

How do I use this to solve the second-order equation?

asked 2022-04-30

${\mathrm{log}}_{3}\left(\frac{{x}^{9}{y}^{8}}{7}\right)$

A) $9{\mathrm{log}}_{3}\left(x\right)+8{\mathrm{log}}_{3}\left(y\right)-{\mathrm{log}}_{3}\left(7\right)$

B) $9{\mathrm{log}}_{3}\left(x\right)-8{\mathrm{log}}_{3}\left(y\right)-{\mathrm{log}}_{3}\left(7\right)$

C) $\left(9{\mathrm{log}}_{3}\right(x\left)\right)\left(8{\mathrm{log}}_{3}\right(y\left)\right)-{\mathrm{log}}_{3}\left(7\right)$

D) $9{\mathrm{log}}_{3}\left(x\right)+8{\mathrm{log}}_{3}\left(y\right)-{\mathrm{log}}_{3}\left(7\right)$

asked 2022-03-29

(ad≥ + 2ycost = coser?t

asked 2022-04-02

Let f be the function from R to R defined by f(x) = x2 •

Find

a) f-1 ({1}).

b) f-1 ({x \ 0 < x < I }).

c) f-1 ({x \ x > 4}).

asked 2022-03-22

Let $a}_{1},{b}_{1$ be two real numbers such that $0<{a}_{1}<{b}_{1}$. For $n\ge 1$, we define $a}_{n+1}={\left({a}_{n}{b}_{n}\right)}^{\frac{1}{2}$ and ${b}_{n+1}=\frac{({a}_{n}+{b}_{n})}{2}$

a) Prove that the sequence $\left\{{a}_{n}\right\}n\in N$ is monotonically increasing and that the sequence $\left\{{b}_{n}\right\}n\in N$ is monotonically decreasing.

b) Show that the sequences $\left\{{a}_{n}\right\}$ and $\left\{{b}_{n}\right\}$ are bounded.

c) Deduce that the two sequences converge and prove that they converge to the same limit.

asked 2022-03-27

Find the 51st term of the arithmetic sequence $29,9,-11,\mathrm{.}\mathrm{.}\mathrm{.}$29,9,−11,...