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3 years ago

I need help please and thank you

Mathematics

1 answer:

Korolek [52]3 years ago

5 0

Step-by-step explanation:

the radius of 12is6

a=3.14×6^2=11304

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What is the sum of the first five terms of the geometric sequence in which

garri49 [273]

Answer:

1/4

Step-by-step explanation:

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3 years ago

A _____________________ variable _________________ on an ____________________ variable.

Mkey [24]

A dependent variable depends on an independent variable

7 0

3 years ago

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

Herbert has sold 99, 37, 86, and 73 copeirs in the last 4 months, respectivly. How many copiers will he need to sell this month

jolli1 [7]

Answer:

Therefore 80 ceperies will he need to sell this month.

Step-by-step explanation:

Average: Average is the ratio of sum of all numbers to the total number present in the data.

Given that Herbert has sold 99, 37, 86 and 73 copeirs in the last 4 months.

Let he need to sell x copeirs in this month.

According to the problem,

$\frac{99+37+86+73+x}{5}=75$

⇒ 99+37+86+73+x= 75×5

⇒295 + x= 375

⇒x = 375 - 295

⇒ x= 80

Therefore 80 ceperies will he need to sell this month.

3 0

3 years ago

Please help. I added a picture.

tangare [24]

its the 3rd answer i think

3 0

3 years ago

Read 2 more answers