# Get help with andom variable equations

Recent questions in Random variables
Kaycee Roche 2021-01-16 Answered

### A population of values has a normal distribution with $$\displaystyle\mu={200}$$ and $$\displaystyle\sigma={31.9}$$. You intend to draw a random sample of size $$\displaystyle{n}={11}$$. Find the probability that a sample of size $$\displaystyle{n}={11}$$ is randomly selected with a mean less than 226.9. $$\displaystyle{P}{\left({M}{<}{226.9}\right)}=$$? Write your answers as numbers accurate to 4 decimal places.

Dillard 2021-01-15 Answered

### The random variable X follows a normal distribution $$\displaystyle?{\left({20},{102}\right)}$$. Find $$\displaystyle{P}{\left({10}{<}?{<}{35}\right)}$$,

glamrockqueen7 2021-01-13 Answered

### Explain the rules 3 and 4 in sum of several random variables.

mattgondek4 2021-01-10 Answered

### A population of values has a normal distribution with mean =136.4 and standard deviation =30.2. A random sample of size $$\displaystyle{n}={158}$$ is drawn. Find the probability that a single randomly selected value is greater than 135. Roung your answer to four decimal places. $$\displaystyle{P}{\left({X}{>}{135}\right)}=$$?

nicekikah 2021-01-06 Answered

### If X and Y are random variables and c is any constant, show that $$E(cX)=cE(X)$$.

Line 2021-01-05 Answered

### A population of values has a normal distribution with $$\displaystyle\mu={99.6}$$ and $$\displaystyle\sigma={35.1}$$. You intend to draw a random sample of size $$\displaystyle{n}={84}$$. Find the probability that a sample of size $$\displaystyle{n}={84}$$ is randomly selected with a mean between 98.5 and 100.7. $$\displaystyle{P}{\left({98.5}{<}\overline{{{X}}}{<}{100.7}\right)}=$$? Write your answers as numbers accurate to 4 decimal places.

SchachtN 2021-01-05 Answered

### If X and Y are random variables and c is any constant, show that $$E(X-Y)=E(X)-E(Y)$$.

Tobias Ali 2021-01-02 Answered

### The length of time ,in minutes, for an airplane to obtain clearance for take off at a certainairport is a random variable Y=3X-2, where X has the density function $$f(x)=\begin{cases}\frac{1}{4}e^{\frac{-x}{4}},x>0\\0,\text{else where}\end{cases}$$ Find the mean and variance of the random variable Y?

emancipezN 2020-12-30 Answered

### Consider a set of 20 independent and identically distributed uniform random variables in the interval (0,1). What is the expected value and variance of the sum, S, of these random variables? Select one: a.$$\displaystyle{E}{\left({S}\right)}={10}$$, $$\displaystyle{V}{a}{r}{\left({S}\right)}={1.66667}$$ b.$$\displaystyle{E}{\left({S}\right)}={200}$$, $$\displaystyle{V}{a}{r}{\left({S}\right)}={16.6667}$$ c.$$\displaystyle{E}{\left({S}\right)}={100}$$, $$\displaystyle{V}{a}{r}{\left({S}\right)}={200}$$ a.$$\displaystyle{E}{\left({S}\right)}={10}$$, $$\displaystyle{V}{a}{r}{\left({S}\right)}={12}$$

glasskerfu 2020-12-30 Answered

### Whether the statement is true or false. Rewrite it as a true statement if it is false.

coexpennan 2020-12-29 Answered

### CNBC recently reported that the mean annual cost of auto insurance is $998. Assume the standard deviation is$298. Find the probability that a single randomly selected value is less than \$985. $$\displaystyle{P}{\left({X}{<}{985}\right)}=$$? Write your answers as numbers accurate to 4 decimal places.

tabita57i 2020-12-28 Answered

### Meaning for F and M assumed as independent random variables in context. F and M are independent random variables. For F: Mean, $$\mu_{F} = 120$$

Harlen Pritchard 2020-12-25 Answered

### A population of values has a normal distribution with $$\displaystyle\mu={13.7}$$ and $$\displaystyle\sigma={22}$$. You intend to draw a random sample of size $$\displaystyle{n}={78}$$. Find the probability that a sample of size $$\displaystyle{n}={78}$$ is randomly selected with a mean less than 11.5. $$\displaystyle{P}{\left({M}{<}{11.5}\right)}=$$? Write your answers as numbers accurate to 4 decimal places.

avissidep 2020-12-22 Answered

### A population of values has a normal distribution with $$\displaystyle\mu={77}$$ and $$\displaystyle\sigma={32.2}$$. You intend to draw a random sample of size $$\displaystyle{n}={15}$$ Find the probability that a sample of size $$\displaystyle{n}={15}$$ is randomly selected with a mean between 59.5 and 98.6. $$\displaystyle{P}{\left({59.5}{<}\overline{{{X}}}{<}{98.6}\right)}=$$? Write your answers as numbers accurate to 4 decimal places.

ankarskogC 2020-12-15 Answered

### A population of values has a normal distribution with $$\displaystyle\mu={26.8}$$ and $$\displaystyle\sigma={33.8}$$. You intend to draw a random sample of size $$\displaystyle{n}={89}$$. Find the probability that a sample of size $$\displaystyle{n}={89}$$ is randomly selected with a mean between 17.1 and 25. $$\displaystyle{P}{\left({17.1}{<}{M}{<}{25}\right)}=$$? Write your answers as numbers accurate to 4 decimal places.

Zoe Oneal 2020-12-13 Answered

### For a population with a mean of $$\displaystyle\mu={100}$$ and a standard deviation of $$\displaystyle\sigma={20}$$, Find the X values. $$\displaystyle{z}=+{1.80}$$.

chillywilly12a 2020-12-09 Answered

### For a population with a mean of $$\displaystyle\mu={100}$$ and a standard deviation of $$\displaystyle\sigma={20}$$, Find the X values. $$\displaystyle{z}=-{.40}$$.

Isa Trevino 2020-12-07 Answered

### A population of values has a normal distribution with $$\displaystyle\mu={99.6}$$ and $$\displaystyle\sigma={35.1}$$. You intend to draw a random sample of size $$\displaystyle{n}={84}$$. Find the probability that a single randomly selected value is between 98.5 and 100.7. $$\displaystyle{P}{\left({98.5}{<}{X}{<}{100.7}\right)}=$$? Write your answers as numbers accurate to 4 decimal places.

shadsiei 2020-12-06 Answered

### A population of values has a normal distribution with $$\displaystyle\mu={13.2}$$ and $$\displaystyle\sigma={5}$$. You intend to draw a random sample of size $$\displaystyle{n}={60}$$. Find the probability that a sample of size $$\displaystyle{n}={60}$$ is randomly selected with a mean between 11.5 and 14. $$\displaystyle{P}{\left({11.5}{<}{M}{<}{14}\right)}=$$? Write your answers as numbers accurate to 4 decimal places.

Tahmid Knox 2020-12-06 Answered

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