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3 years ago

Solve the proportion 7/5=21/x (show work/explain how u got it please)

Mathematics

1 answer:

Anvisha [2.4K]3 years ago

5 0

Answer:

x = 15

Step-by-step explanation:

I am going to use the "butterfly" method for proportions

(there is another type of butterfly method that is different, I am not sure if there is another name for this method, sorry!)

$\frac{7}{5} = \frac{21}{x}$

Multiply the:

- top left by the bottom right

-the top right by the bottom left

and then:

- set them equal to each other

So we will <u>multiply 7 by x and 21 by 5</u> (if this doesn't make sense tell me and I will explain it even more!)

7x = 21 * 5

7x = 105

(Divide both sides by 7) <em>x = 15</em>

Hope this helps, have a nice day! :D <3

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Behavior patterns which are already present at birth are called ____

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Answer:

instincts

Step-by-step explanation:

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3 years ago

P-value test and Ctitical Value test are identical. P-value and Critical value are two different names for the same steps. They

creativ13 [48]

Answer:

Option B - False

Step-by-step explanation:

Critical value is a point beyond which we normally reject the null hypothesis. Whereas, P-value is defined as the probability to the right of respective statistic which could either be Z, T or chi. Now, the benefit of using p-value is that it calculates a probability estimate which we will be able to test at any level of significance by comparing the probability directly with the significance level.

For example, let's assume that the Z-value for a particular experiment is 1.67, which will be greater than the critical value at 5% which will be 1.64. Thus, if we want to check for a different significance level of 1%, we will need to calculate a new critical value.

Whereas, if we calculate the p-value for say 1.67, it will give a value of about 0.047. This p-value can be used to reject the hypothesis at 5% significance level since 0.047 < 0.05. But with a significance level of 1%, the hypothesis can be accepted since 0.047 > 0.01.

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3 years ago

Which of the following best describes the solution to the system of equations below?

OverLord2011 [107]

Answer: OPTION A

Step-by-step explanation:

The equation of the line in slope-intercept form is:

$y=mx+b$

Where m is the slope and b the y-intercept.

Solve for y from each equation:

$\left \{ {{5y=-4x+7} \atop {10y=-8x+14}} \right.\\\\\left \{ {{y=\frac{-4}{5}x+\frac{7}{5}} \atop {y=\frac{-8}{10}x+\frac{14}{10}}} \right.\\\\\left \{ {{y=\frac{-4}{5}x+\frac{7}{5}} \atop {y=\frac{-4}{5}x+\frac{7}{5}}} \right.$

As you can see the slope and the y-intercept of each equation are equal, this means that both are the exact same line. Therefore, you can conclude that the system has infinitely many solutions.

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3 years ago

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nirvana33 [79]

Answer:

24 miles.

Step-by-step explanation:

Jackie traveled four times as many miles by bus as by foot. This means that the number of miles travelled by bus is 4 units, and the number of miles travelled by foot is 1 unit.

Jackie traveled three times as many miles by train as by bus. We know that the number of miles travelled by bus is 4 units, so the number of miles travelled by train is $4\times3=12$ units.