Combine the like terms to create an equivalen -k + 3k Stuck? Watch a video or use a hint.

USA Today reports that about 25% of all prison parolees become repeat offenders. Alice is a social worker whose job is to counse

pychu [463]

Answer:

a) $P(X=0)=(4C0)(0.75)^0 (1-0.75)^{4-0}=0.0039$

$P(X=1)=(4C1)(0.75)^1 (1-0.75)^{4-1}=0.0469$

$P(X=2)=(4C2)(0.75)^2 (1-0.75)^{4-2}=0.211$

$P(X=3)=(4C3)(0.75)^2 (1-0.75)^{4-3}=0.422$

$P(X=4)=(4C4)(0.75)^2 (1-0.75)^{4-4}=0.316$

b) $E(X) = np = 4*0.75=3$

c) $Sd(X) =\sqrt{np(1-p)}=\sqrt{4*0.75*(1-0.75)}=0.866$

d) $P(X \geq 3) \geq 0.98$

And the dsitribution that satisfy this is $X\sim Binom(n=9,p=0.75$

Step-by-step explanation:

Previous concepts

The binomial distribution is a "DISCRETE probability distribution that summarizes the probability that a value will take one of two independent values under a given set of parameters. The assumptions for the binomial distribution are that there is only one outcome for each trial, each trial has the same probability of success, and each trial is mutually exclusive, or independent of each other".

Let X the random variable of interest, on this case we now that:

$X \sim Binom(n=4, p=1-0.25=0.75)$

The probability mass function for the Binomial distribution is given as:

$P(X)=(nCx)(p)^x (1-p)^{n-x}$

Where (nCx) means combinatory and it's given by this formula:

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

Part a

$P(X=0)=(4C0)(0.75)^0 (1-0.75)^{4-0}=0.0039$

$P(X=1)=(4C1)(0.75)^1 (1-0.75)^{4-1}=0.0469$

$P(X=2)=(4C2)(0.75)^2 (1-0.75)^{4-2}=0.211$

$P(X=3)=(4C3)(0.75)^2 (1-0.75)^{4-3}=0.422$

$P(X=4)=(4C4)(0.75)^2 (1-0.75)^{4-4}=0.316$

Part b

The expected value is givn by:

$E(X) = np = 4*0.75=3$

Part c

For the standard deviation we have this:

$Sd(X) =\sqrt{np(1-p)}=\sqrt{4*0.75*(1-0.75)}=0.866$

Part d

For this case the sample size needs to be higher or equal to 9. Since we need a value such that:

$P(X \geq 3) \geq 0.98$

And the dsitribution that satisfy this is $X\sim Binom(n=9,p=0.75$

We can verify this using the following code:

"=1-BINOM.DIST(3,9,0.75,TRUE)" and we got 0.99 and the condition is satisfied.

4 0

3 years ago

What is the formula to find the volume of the solid ?

tester [92]

Answer:

Step-by-step explanation:

This solid figure is a cone,

Volume=(πr²H)/3 cubic units

r ----> radius

H -------> height

6 0

3 years ago

Could I get some help? QUESTION: This table shows the profit for a company (in millions of dollars) in different years.

Pani-rosa [81]

Answer:

17 million

Step-by-step explanation:

-0.34( $8^{2}$ ) + 4.43(8) + 3.46

-21.76 + 35.44 + 3.46

13.68 + 3.46

17.14

Answer: C 17 million

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7 0

2 years ago

Solve for m. 8m+95<−87m+5

tiny-mole [99]

Answer:

m < - $\frac{18}{19}$

Step-by-step explanation:

8m + 95 < -87m + 5

8m + 87m < 5 - 95

95m < -90

m < - $\frac{90}{95}$

Simplifying gives;

m < - $\frac{18}{19}$

3 0

3 years ago

Read 2 more answers

If discriminant is zero, how many solutions do I have?

kap26 [50]

You would have one repeating real solution.

3 0

3 years ago