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4 years ago

What is-2x+6y=6 7x+8y=-6?

1 answer:

3 0

We can solve this by substitution

-2x=6-6y

-2x/-2=(6-6y)/-2
x= -3+3y

7(-3+3y)+8y=-6
-21+21y+8y=-6
29y=15
y=15/29

-2x+6(15/29)=6
-2x+90/29=6
-2x=6-90/29
-2x= 174/29-90/29
-2x= 84/29
-2x(29)=(84/29)29
-54x=84
x= -84/54
x= -14/9

so x= -14/9
y= 15/29

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According to government data, 20% of employed women have never been married. If 10 employed women are selected at random, what i

Ierofanga [76]

Answer:

a) $P(X=2) = (10C2) (0.2)^2 (1-0.2)^{10-2}= 0.302$

b) $P(X\leq 2) = P(X=0) + P(X=1) +P(X=2)$

$P(X=0) = (10C0) (0.2)^0 (1-0.2)^{10-0}= 0.107$

$P(X=1) = (10C1) (0.2)^1 (1-0.2)^{10-1}= 0.268$

$P(X=2) = (10C2) (0.2)^2 (1-0.2)^{10-2}= 0.302$

And replacing we got:

$P(X\leq 2) = 0.107+0.268+0.302=0.678$

c) For this case we want this probability:

$P(X\geq 8) = P(X=8) + P(X=9) +P(X=10)$

But for this case the probability of success is p =1-0.2= 0.8

We can find the individual probabilities and we got:

$P(X=8) = (10C8) (0.8)^8 (1-0.8)^{10-8} =0.302$

$P(X=9) = (10C9) (0.8)^9 (1-0.8)^{10-9} =0.268$

$P(X=10) = (10C10) (0.8)^{10} (1-0.8)^{10-10} =0.107$

And replacing we got:

$P(X \geq 8) = 0.677$

And replacing we got:

$P(X\geq 8)=0.0000779$

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:

$X \sim Bin (n=10 ,p=0.2)$

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:

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

Solution to the problem

Let X the random variable "number of women that have never been married" , on this case we now that the distribution of the random variable is:

$X \sim Binom(n=10, p=0.2)$

Part a

We want to find this probability:

$P(X=2)$

And using the probability mass function we got:

$P(X=2) = (10C2) (0.2)^2 (1-0.2)^{10-2}= 0.302$

Part b

For this case we want this probability:

$P(X\leq 2) = P(X=0) + P(X=1) +P(X=2)$

We can find the individual probabilities and we got:

$P(X=0) = (10C0) (0.2)^0 (1-0.2)^{10-0}= 0.107$

$P(X=1) = (10C1) (0.2)^1 (1-0.2)^{10-1}= 0.268$

$P(X=2) = (10C2) (0.2)^2 (1-0.2)^{10-2}= 0.302$

And replacing we got:

$P(X\leq 2) = 0.107+0.268+0.302=0.678$

Part c

For this case we want this probability:

$P(X\geq 8) = P(X=8) + P(X=9) +P(X=10)$

But for this case the probability of success is p =1-0.2= 0.8

We can find the individual probabilities and we got:

$P(X=8) = (10C8) (0.8)^8 (1-0.8)^{10-8} =0.302$

$P(X=9) = (10C9) (0.8)^9 (1-0.8)^{10-9} =0.268$

$P(X=10) = (10C10) (0.8)^{10} (1-0.8)^{10-10} =0.107$

And replacing we got:

$P(X \geq 8) = 0.677$

3 0

3 years ago

Find P(x)=... polynomial

Aneli [31]

Answer: D) P(x) = -23

Step-by-step explanation:

Substitute 2 for x:

1 - 2(2)^2-3(2)^2+4(2)

Exponent

1-2(4)-3(8)+4(2)

Multiply

1-8-24+8

Combine like terms

-23

<em>Hope it helps <3</em>

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3 years ago

Which relation is a function?

Julli [10]

The bottom left is the function.

7 0

3 years ago

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For each of these triples, find if they could be the lengths of the sides of a right triangle.

frutty [35]

A is the correct answer

7 0

4 years ago

Suppose the band sells erasers for $2 per package and pencils for $5 per package. The band sells 220 packages in all and earns a

garik1379 [7]

Let e=erasers and p=pencils. So we know the total amount of erasers plus pencils sold is equal to 220. Therefore,

$e + p = 220$
We also know the cost of erasers and pencils totaled to $695 in earnings and so:

$2e + 5p = 695$
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5 0

3 years ago