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3 years ago

PLEASE HELP !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Mathematics

1 answer:

Bond [772]3 years ago

8 0

Answer:

$R = \frac {3ST}{2S + T}$

Step-by-step explanation:

Given the equation;

$\frac {3}{R} - \frac {1}{S} = \frac {2}{T}$

Rearranging the equation, we have;

$\frac {3}{R} = \frac {2}{T} + \frac {1}{S}$

Lowest common multiple (LCM) of S and T is ST.

$\frac {3}{R} = \frac {2S + T}{ST}$

Cross-multiplying, we have;

$3ST = R(2S + T)$

Making R, the subject of formula;

$R = \frac {3ST}{2S + T}$

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The mean amount of water in 5 containers is 620 ml the total amount of water in 4 q of the containers is 2750 what is the amount

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The correct answer is:

350 ml.

Explanation:

Let x be the amount in the fifth container.

The mean is found by adding all of the amounts together and dividing by the number of containers (in this problem, 5). We know that the total from the other 4 containers is 2750; add this to x, our unknown number. Then we divide by 5 to arrive at our answer of 620.

Algebraically,
 $\frac{2750+x}{5}=620$ 

To solve, multiply both sides by 5:
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Subtract 2750 from both sides:
2750+x-2750=3100-2750
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There are 350 ml in the fifth container.

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3 years ago

6/10+6/100= how do i do this problem

olya-2409 [2.1K]

Answer:

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Step-by-step explanation:

As division is always done before addition you would divide the 6 by 10 and then divide the 6 by 100. 6 divided by 10 is equal to 0.6 as you move the decimal point to the left once. 6 divided by 100 is equal to 0.06 as you move the decimal point to the left twice. Addition is always done after division so you would add 0.6 and 0.06 together. This will give you 0.66 as your answer.

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The least-squares regression model y =−3.4+5.2x and correlation coefficient r=−0.66 were calculated for a set of bivariate data

Makovka662 [10]

Answer:

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

For this case the value of r = -0.66

Now we can calculate the determination coeffcient:

$r^2 = (-0.66)^2 = 0.4356$

And then we can conclude that 43.56% of the variation in y can be explained by the explanatory variable

And then 100-43.56 = 56.44 % of the variation in y that cannot be explained by the explanatory variable

Step-by-step explanation:

For this case we need to calculate the slope with the following formula:

$m=\frac{S_{xy}}{S_{xx}}$

Where:

$S_{xy}=\sum_{i=1}^n x_i y_i -\frac{(\sum_{i=1}^n x_i)(\sum_{i=1}^n y_i)}{n}$

$S_{xx}=\sum_{i=1}^n x^2_i -\frac{(\sum_{i=1}^n x_i)^2}{n}$

$\bar x= \frac{\sum x_i}{n}$

$\bar y= \frac{\sum y_i}{n}$

And we can find the intercept using this:

$b=\bar y -m \bar x$

And the model obtained for this case is:

$y = -3.4 +5.2 x$

The correlation coefficient is a "statistical measure that calculates the strength of the relationship between the relative movements of two variables". It's denoted by r and its always between -1 and 1.

And in order to calculate the correlation coefficient we can use this formula:

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

For this case the value of r = -0.66

Now we can calculate the determination coeffcient:

$r^2 = (-0.66)^2 = 0.4356$

And then we can conclude that 43.56% of the variation in y can be explained by the explanatory variable

And then 100-43.56 = 56.44 % of the variation in y that cannot be explained by the explanatory variable

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3 years ago