Suppose that X is a normal random variable with mean 5. If P{X>9}=.2, approximat

We wish to estimate what percent of adult residents in a certain county are parents. Out of 600 adult residents sampled, 192 had kids. Based on this, plot a $99\mathrm{\%}$ confidence interval for the proportion of adult residents who are parents in a given county.
Express your answer in the form of three inequalities. Give your answers in decimal fractions up to three places ${\displaystyle <p<}$ Express the same answer using a point estimate and a margin of error. Give your answers as decimals, to three places.
${\displaystyle p=\pm }$

A population of values has a normal distribution with ${\displaystyle \mu =133.5}$ and ${\displaystyle \sigma =5.2}$. You intend to draw a random sample of size ${\displaystyle n=230}$.
Find the probability that a single randomly selected value is between 133.6 and 134.1.
${\displaystyle P\left(133.6<X<134.1\right)=}$?
Write your answers as numbers accurate to 4 decimal places.

What are the mean and standard deviation of a binomial probability distribution with n=11 and ${\displaystyle p=\frac{19}{23}}$?

On a multiple choice test with 19 questions, each question has four possible answers, one of which is correct. For students who guess at all answers how do you find the mean for the number of correct answers?

Two random variables X and Y with joint density function given by:
$f(x,y)=\{\begin{array}{ll}\frac{1}{3}(2x+4y)& 0\le x,\le 1\\ 0& elsewhere\end{array}$
Find the marginal density of X.

If X is a normal random variable with parameters
${\displaystyle \mu =10}$
and
${\displaystyle {\sigma }^2=36}$
, compute P[X>5]

A population of values has a normal distribution with ${\displaystyle \mu =129.7}$ and ${\displaystyle \sigma =7.7}$. You intend to draw a random sample of size ${\displaystyle n=10}$.
Find the probability that a single randomly selected value is less than 130.9.
${\displaystyle P\left(X<130.9\right)=}$?
Write your answers as numbers accurate to 4 decimal places.