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3 years ago

9

Solve the system of equations. 2x + 7y = 3 x= -4y

1 answer:

I am Lyosha [343]3 years ago

5 0

Answer:

(12, -3)

Step-by-step explanation:

You can solve it algebraically or graphically. Graphically you find the intersection point. Algebraically with substitution/elimination.

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Help geometry is so hard for me

Nata [24]

Answer is 5<span>√2 (second choice)
c^2 = 5^2 + 5^2
c^2 = 50
c = </span><span>√50
c = </span>√25 <span>√2
c = 5</span><span>√2</span>

5 0

3 years ago

Grading managers. Some companies "grade on a bell curve" to compare the performance of their managers and professional workers.

Monica [59]

Answer:

$\mu = 250, \sigma = 175.781$

Step-by-step explanation:

Previous concepts

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".

Solution to the problem

Let X the random variable that represent the grades of a population, and for this case we know the distribution for X is given by:

$X \sim N(\mu,\sigma)$

For this case we have two conditions given:

$P(X$

$P(X>475) = 0.1$ or equivalently $P(X$

And the best way to solve this problem is using the normal standard distribution and the z score given by:

$z=\frac{x-\mu}{\sigma}$

So we can find a value from the normal standard distribution that accumulates 0.1 and 0.9 of the area in the left, for this case the two values are:

$z= -1.28, z=-1.28$

We can verify that P(Z<-1.28) =0.1[/tex] and P(Z<1.28) =0.9[/tex]

And then using the z score we have the following formulas:

$-1.28 = \frac{25 -\mu}{\sigma}$ (1)

$1.28 = \frac{475 -\mu}{\sigma}$ (2)

If we add equations (1) and (2) we got:

$\frac{25 -\mu}{\sigma} + \frac{475 -\mu}{\sigma} =0$

We can multiply both sides of the equation by $\sigma$ and we got:

$25+ 475 -2 \mu = 0$

$\mu = \frac{500}{2}= 250$

And then we can find the standard deviation for example from equation (1) and we got:

$\sigma = \frac{25-250}{-1.28}=175.781$

So then the answer would be:

$\mu = 250, \sigma = 175.781$

3 0

3 years ago

I will give brainliest if you sub and stay subbed to JD Outdoors & Gaming

NeTakaya

Answer:

hello again

Step-by-step explanation:

8 0

3 years ago

Three times the square of the difference of x and 6 is 12

Elis [28]

Answer:

Equation: $3(x-6)^2=12$

Solutions: $x=4\text{ or }x=8$

Step-by-step explanation:

Unknown variable $= x$

Difference of x and 6 $= x - 6$

Square of the difference of x and 6 $=(x-6)^2$

Three times the square of the difference of x and 6 $=3(x-6)^2$

Three times the square of the difference of x and 6 is 12, then

$3(x-6)^2=12$

Divide this equation by 3:

$(x-6)^2 =4$

Now

$x-6=2\text{ or }x-6=-2\\ \\x=2+6\text{ or }x=-2+6\\ \\x=8\text{ or }x=4$

8 0

3 years ago

Read 2 more answers

Everyone shop in her favorite store target she buy T-shirts in pair of jeans that cost $20 she’s been a total of 80 or purchase

kumpel [21]

Step-by-step explanation:

so you divide

$80 \div 20 = 4$

so each t-shirt costs 4$

5 0

2 years ago