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mario62 [17]
3 years ago
8

HELP PLEASE someone its importent

Mathematics
1 answer:
elena-s [515]3 years ago
5 0

Answer:

Step-by-step explanation:

<u>Expression on the board :</u>

12.2x + 50.6 y + 3(1.4x - 2.6y)\\\\= 12.2x + 50.6y + 4.2x - 7.8y\\\\= 16.4x + 42.8y

<u>Expression by the student </u>:

<em><u> Expression 1 </u></em>:

4 ( 4.1x + 10.7 y ) \\\\=  ( 4 \times 4.1x ) + ( 4 \times 10.7 y)\\\\= 16.4x + 42.8y\\\\

The expression 1 is equivalent to the expression on the board. Because the coefficients of x and y are same on both.

<em><u>Expression 2 :</u></em>

<em><u /></em>2 ( 6.1x + 25.3 y + 2.1x -3.9y)\\\\= 2 ( 8.2x + 21.4y)\\\\=( 2 \times 8.2x ) + (2 \times 21.4y)\\\\= 16.4x + 42.8y<em><u /></em>

The expression 2 is also equivalent to the expression on the board. Because the coefficients of x and y are the same.

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Vail Resorts pays part-time seasonal employees at ski resorts on an hourly basis. At a certain mountain, the hourly rates have a
notsponge [240]

Answer:

z=0.842

And if we solve for a we got

\mu=13.16 +0.842*3=15.69

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 hourly rates of a population, and for this case we know the distribution for X is given by:

X \sim N(\mu,3)  

For this part we want to find a value a, such that we satisfy this condition:

P(X>13.16)=0.20   (a)

P(X   (b)

Both conditions are equivalent on this case. We can use the z score again in order to find the value a.  

As we can see on the figure attached the z value that satisfy the condition with 0.80 of the area on the left and 0.20 of the area on the right it's z=0.842. On this case P(Z<0.842)=0.8 and P(z>0.842)=0.20

If we use condition (b) from previous we have this:

P(X  

P(z

But we know which value of z satisfy the previous equation so then we can do this:

z=0.842

And if we solve for a we got

\mu=13.16 +0.842*3=15.69

3 0
2 years ago
The following table shows the length and width of two rectangles:
faltersainse [42]
The perimeter of these can be found by adding length and width and then multiplying by two. 

Rectangle A: (with all of the variables already doubled)
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So rectangle A's perimeter is 4x + 14.

Rectangle B: (Still with all the variables already doubled)
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And now to subtract the two.
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So it would be C.
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vovangra [49]

Answer:

40.49cm²

Step-by-step explanation:

I hope it helps

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