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4 years ago

ANSWER ASAP

Mathematics

2 answers:

Aliun [14]4 years ago

8 0

7a - a ^2 - (-4 + 3a^2)
= 7a - a ^2 + 4 - 3a^2
= - 4a^2 + 7a + 4

answer
C) -4a^2 + 7a + 4

vaieri [72.5K]4 years ago

3 0

Answer:

C) -4a^2 + 7a + 4

Step-by-step explanation:

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The answer is A.$0.09!

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3 years ago

The surface areas of two similar hexagonal prisms are 882cm² and 1,058 cm²? What is the scale factor of the smaller

max2010maxim [7]

Answer:

scale factor of the smaller prism to the larger prism is B. 21/23

Step-by-step explanation:

Given

surface areas of two similar hexagonal prisms are 882cm² and 1,058 cm²?

scale factor is ratio of sides of two similar objects

thus scale factor for given prism will be = side of smaller prism / side of larger prism

in general rule

If shape of solid has scale factor of k

scale factor of area = k²

scale factor of volume = k³

_____________________________

Given in the problem area of two prism is given

we know area = side^2

scale factor of area = k²

k^2 = area of smaller prism / area of larger prism

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3 years ago

Suppose that the waiting time for a license plate renewal at a local office of a state motor vehicle department has been found t

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Answer:

$a=30 +1.04*8=38.32$

So the value of height that separates the bottom 85% of data from the top 15% is 38.32.

C) 38.32

Step-by-step explanation:

1) 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".

2) Solution to the problem

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

$X \sim N(30,8)$

Where $\mu=30$ and $\sigma=8$

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

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

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

$P(X>a)=0.15$ (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 0.85 of the area on the left and 0.15 of the area on the right it's z=1.04. On this case P(Z<1.04)=0.85 and P(z>1.04)=0.15

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

$P(X$