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3 years ago

What is the length of x? What is the length of EF? Only enter numbers in the answer boxes below:

Mathematics

1 answer:

ioda3 years ago

8 0

Focus on triangles DFC and DFE:

They are both right triangles because DF is perpendicular to EC

DC=DE

DF is a common side

So, the two triangles are congruent. It follows that CF=FE, and in particular

$8x=3x+15 \iff 5x=15 \iff x=3$

And since x=3, the length of EF is

$3x+15=3\cdot 3+15=24$

You might be interested in

If the distribution is really (5.43,0.54)

defon

Answer:

0.7486 = 74.86% observations would be less than 5.79

Step-by-step explanation:

I suppose there was a small typing mistake, so i am going to use the distribution as N (5.43,0.54)

Problems of normally distributed samples can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

The general format of the normal distribution is:

N(mean, standard deviation)

Which means that:

$\mu = 5.43, \sigma = 0.54$

What proportion of observations would be less than 5.79?

This is the pvalue of Z when X = 5.79. So

$Z = \frac{X - \mu}{\sigma}$

$Z = \frac{5.79 - 5.43}{0.54}$

$Z = 0.67$

$Z = 0.67$ has a pvalue of 0.7486

0.7486 = 74.86% observations would be less than 5.79

7 0

2 years ago

Help pls giving BRAINLIEST!!!

finlep [7]

$3 \sqrt{3}$

please mark me as brainlist

5 0

2 years ago

Why the area and the perimeter are not both multiplied by the same factor.

lina2011 [118]

Answer:

Step-by-step explanation:

It might be the length of one of the sides of a polygon (a figure with straight sides) or the radius of a circle. ... You can find the perimeter of a regular octagon (8-sided figure with equal sides) by multiplying the length of one of the sides by 8. The area of a figure is the measure of how large its surface is. I think btw if its wrong sorry :)

6 0

2 years ago

Please help! With steps included :)

Len [333]

Answer:

Top question: -7°

Bottom question : 18°

Step-by-step explanation:

Top question:

The base angles of am isosceles triangle are congruent:

x + 46 = 39 because the base angles of an isosceles triangle are congruent

x + 46° = 39°

x = -7°

Bottom question

The missing angle is 3x because the base angles are congruent

To find the value of x, we must add all the angles inside the triangle, and find the value of x that makes it equal to 180°

3x + 3x + 4x = 180°

10x = 180°

x = 18°

Sorry for the late post!

-Chetan K

8 0

2 years ago

Mandvil has one standard quarter and one special quarter with a Head on both sides. He selects one of these two coins at random,

Lana71 [14]

The probability that he selected the special quarter is 87.5%.

<h3><u /></h3><h3><u>Probability</u></h3>

Given that Mandvil has one standard quarter and one special quarter with a Head on both sides, and he selects one of these two coins at random, and without looking at it first, he flips the coin three times, to determine, if he flips a Head three straight times, what is the probability that he selected the special quarter, the following calculation must be made:

1 - (standard quarter) = X
1 - (0.50^3) = X
1 - 0.125 = X
0.875 = X
0.875 x 100 = 87.5

Therefore, the probability that he selected the special quarter is 87.5%.

Learn more about probability in brainly.com/question/24217562

3 0

1 year ago