What is 1/2 of 22 and 2/3 of 16

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

The cost to mail a letter today is $0.52 and the rate of inflation each year is 2%. In 40 years, how much will you have to pay?

Nastasia [14]

Answer:

94 cents?

Step-by-step explanation:

2%*40=80%

1.80*0.52=0.936

In 40 years, mail may cost about 94 cents.

(I think this is the correct answer ://)

6 0

3 years ago

What is the length of AC?

Alenkasestr [34]

So in order to find line AC you must find line AD and DC then plus them together.

to find AD use Pythagoras theorem
a^2 = c^2 - b^2
AD^2 = 7.5^2 - 6.5^2
AD^2 = 56.25 - 42.25
AD^2 = 14
square root both sides to get rid of the ^2
AD ≈ 3.7 or 3.74

Do the same for DC
DC^2 = 10^2 - 6.5^2
DC^2 = 100 - 42.25
DC^2 = 57.75
DC ≈ 7.6

now plus AD and DC which should give u 11.3

5 0

3 years ago

Plzzzzzz help!! I will give brainliest to whoever answers

jarptica [38.1K]

Answer:

4 and -3 i think

Step-by-step explanation:

the dot is on 4 and -3

5 0

3 years ago

Read 2 more answers

PLZ HELP HIVE BRAINLYWho got the better deal in the Columbian Exchange: the Europeans or the Native Americans? Why?

Vitek1552 [10]

Answer:

the Europeans got the better deal from the Colombian Exchange

Step-by-step explanation:

In general, one would have to say that the Europeans got the better deal from the Columbian Exchange in that it facilitated the eventual establishment of colonies in the New World. That's not to say that it was all one-way traffic; however, the people of the New World undoubtedly benefitted in both the short and long-term by the introduction of crops and livestock. But such benefits proved to be more keenly felt by subsequent waves of European settlers than America's indigenous population.

After all, it wasn't much good for Native-Americans to have all these crops and all this livestock if, in due course, there'd be less land available for their use due to increased colonization. The indigenous peoples also suffered terribly from the introduction of diseases such as measles and smallpox, for which they had no natural immunity. It's difficult, then, to avoid the conclusion that the Europeans got the better deal from the Columbian Exchange (as it was probably intended that they should).

simply -

The Natives did benefit, but only for a short while, and the Europeans benefited the most

Kono Dio Da!!!

7 0

3 years ago