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3 years ago

What is the length of CD? in this diagram ABC ~ EDC

Mathematics

1 answer:

eduard3 years ago

3 0

Answer & Step-by-step explanation:

These triangles are similar. This means that they are going to have the same ratios within their different sides.

AC and CE already have measurements so we are going to find the ratio between them. We can do this by dividing 21 by 7.

21 / 7 = 3

So, since the ratio between AC and CE is 3, then the rest of the triangle has a ratio of 3 with the other triangle.

So, let's set up an equation so we can find the value of x.

21/7 = (20 - x)/x

Cross multiply.

21x = 140 - 7x

Add 7x to both sides of the equation.

28x = 140

Divide 28 from 140.

x = 5

Now that we have the value of x, then we can find the measurement of CD.

The measurement of CD is 5.

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A skirt originally cost $10. How much will it cost if you sell it in Amazon with 25% mark-up price

san4es73 [151]

Answer:

$20.40

Step-by-step explanation:

20% off means that the new price of the skirt will be 80% of the original price:

$30(100% – 20%) = $30(80%)

Converting the percent to a decimal gives:

$30(0.8) = $24.00

There is an additional 15% off the sale price of $24.00, so the final price is 85% of the sale price:

$24(100% – 15%) = $24(85%)

Again converting the percent to a decimal gives:

$24(0.85) = $20.40

5 0

2 years ago

What is the value of the correlation coefficient r of the data set?

enyata [817]

The correct option will be: C) 0.84

Explanation

Formula for Correlation coefficient :

$r= \frac{n(\Sigma xy)-(\Sigma x)(\Sigma y)}{\sqrt{[n\Sigma x^2-(\Sigma x)^2][n\Sigma y^2-(\Sigma y)^2]}}$

First, for each point(x, y), we need to calculate x², y² and xy .

Then, we will find sum all x, y, x², y² and xy, which gives us Σx, Σy, Σx², ∑y² and Σxy

(Please refer to the attached image for the table )

Here we got, ∑x = 44 , ∑y = 183 , ∑x² = 362 , ∑y² = 6575 and ∑xy = 1480

'n' is the total number of data set, which is 7 here.

So, plugging those values into the above formula..........

$r= \frac{n(\Sigma xy)-(\Sigma x)(\Sigma y)}{\sqrt{[n\Sigma x^2-(\Sigma x)^2][n\Sigma y^2-(\Sigma y)^2]}}\\ \\ r=\frac{7(1480)-(44)(183)}{\sqrt{[7(362)-(44)^2][7(6575)-(183)^2]}}\\ \\ r=\frac{10360-8052}{\sqrt{(598)(12536)}}\\ \\ r=\frac{2308}{\sqrt{7496528}}\\ \\ r=0.84$

So, the value of the correlation coefficient is 0.84

4 0

3 years ago

Read 2 more answers

What are the measurements of the two angles in the figure below?

IgorC [24]

Both angles need to equal 180 degrees .

Add them together:

2x +10 + 3x-5 = 180

5X +5 = 180

Subtract 5 from each side:

5x = 175

Divide both sides by 5:

X = 175 / 5

X = 35

Now replace X with 35 in each equation:

2x +10 = 2(35) +10 = 70 +10 = 80

3x-5 = 3(35) - 5 = 105 -5 = 100

The answer is A. 80 and 100

5 0

2 years ago

What number is between 3.16 and 3.17?

VladimirAG [237]

There are multiple answers to this question
Answers: 3.161, 3.162, 3.163, 3.164, 3.165, 3.166, 3.167, 3.168, 3.169
(You can just pick one)

Reason: just look at the place numbers. The number has to be between 3.16 and 3.17. So go to the next place value which is the thousandths place. 3.161-3.169 all are between since they have a 6 in the hundredths place, but does not go over 1.17

4 0

3 years ago

SVEN [57.7K]

Answer:

Answer Is A

Hopefully this help

Step-by-step explanation:

8 0

3 years ago