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1 year ago

Convert 0.45 (5 is a repeating number) to a fraction

Mathematics

1 answer:

Jobisdone [24]1 year ago

3 0

Let the given number be 'x',

$\begin{gathered} x=0.4\bar{5} \\ x=0.45555555\ldots\ldots \end{gathered}$

Multiply both sides by 10,

$\begin{gathered} 10x=4.\bar{5} \\ 10x=4.5555555\ldots\ldots \end{gathered}$

Subtract the equations,

$\begin{gathered} 10x-x=4.5555\ldots-0.45555\ldots \\ 9x=4.5+0.0\bar{5}-(0.4+0.0\bar{5}) \\ 9x=4.5+0.0\bar{5}-0.4-0.0\bar{5} \\ 9x=4.1 \\ 9x=\frac{41}{10} \\ x=\frac{41}{90} \end{gathered}$

Thus, the recurring decimal number is equivalent to the fraction,

$0.4\bar{5}=\frac{41}{90}$

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Find the length of 1 side of square if the area is 49 sq.cm<br> method needed

ladessa [460]

Answer:

It would be 7cm

Step-by-step explanation:

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1 year ago

The accompanying data on x = current density (mA/cm2) and y = rate of deposition (m/min)μ appeared in a recent study.

gtnhenbr [62]

Answer:

a) $r=\frac{4(333)-(200)(5.37)}{\sqrt{[4(12000) -(200)^2][4(9.3501) -(5.37)^2]}}=0.9857$

The correlation coefficient for this case is very near to 1 so then we can ensure that we have linear correlation between the two variables

b) $m=\frac{64.5}{2000}=0.03225$

Now we can find the means for x and y like this:

$\bar x= \frac{\sum x_i}{n}=\frac{200}{4}=50$

$\bar y= \frac{\sum y_i}{n}=\frac{5.37}{4}=1.3425$

$b=\bar y -m \bar x=1.3425-(0.03225*50)=-0.27$

So the line would be given by:

$y=0.3225 x -0.27$

Step-by-step explanation:

Part a

The correlation coeffcient is given by 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 our case we have this:

n=4 $\sum x = 200, \sum y = 5.37, \sum xy = 333, \sum x^2 =12000, \sum y^2 =9.3501$

$r=\frac{4(333)-(200)(5.37)}{\sqrt{[4(12000) -(200)^2][4(9.3501) -(5.37)^2]}}=0.9857$

The correlation coefficient for this case is very near to 1 so then we can ensure that we have linear correlation between the two variables

Part b

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

Where:

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

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

With these we can find the sums:

$S_{xx}=\sum_{i=1}^n x^2_i -\frac{(\sum_{i=1}^n x_i)^2}{n}=12000-\frac{200^2}{4}=2000$

$S_{xy}=\sum_{i=1}^n x_i y_i -\frac{(\sum_{i=1}^n x_i)(\sum_{i=1}^n y_i){n}}=333-\frac{200*5.37}{4}=64.5$

And the slope would be:

$m=\frac{64.5}{2000}=0.03225$

Now we can find the means for x and y like this:

$\bar x= \frac{\sum x_i}{n}=\frac{200}{4}=50$

$\bar y= \frac{\sum y_i}{n}=\frac{5.37}{4}=1.3425$

And we can find the intercept using this:

$b=\bar y -m \bar x=1.3425-(0.03225*50)=-0.27$

So the line would be given by:

$y=0.3225 x -0.27$

4 0

3 years ago

Question:

riadik2000 [5.3K]

Answer:

180

Step-by-step explanation:

3 0

3 years ago

Read 2 more answers

A company produces and sells widgets and gizmos. In January the company sold 350 items for a total of $9,000. If each widget sol

iren [92.7K]

Answer:

The company sold 100 widgets and 250 gizmos.

Step-by-step explanation:

Let $x_1$ be the number of widgets sold and $x_2$ be the number of gizmos sold.

We are told that the company sold 350 items. We can represent this information in an equation as:

$x_1+x_2=350...(1)$

We have been given that a each widget sold for $35 and each gizmo sold for $22. The company sold 350 items for a total of $9,000.

We can represent this information in an equation as:

$35x_1+22x_2=9,000...(2)$

From equation (1), we will get:

$x_2=350-x_1$

Substitute this value in equation (2):

$35x_1+22(350-x_1)=9,000$

$35x_1+7,700-22x_1=9,000$

$13x_1+7,700=9,000$

$13x_1+7,700-7,700=9,000-7,700$

$13x_1=1,300$

$\frac{13x_1}{13}=\frac{1,300}{13}$

$x_1=100$

Therefore, the company sold 100 widgets.

Substitute $x_1=100$ in equation (1):

$100+x_2=350$

$100-100+x_2=350-100$

$x_2=250$

Therefore, the company sold 250 gizmos.

3 0

2 years ago

Read 2 more answers

What irrational number is between 4.47 and 4.48?

shepuryov [24]

Answer: √20 is between 4.47 and 4.48

Step-by-step explanation: Square roots of numbers between perfect squares are irrational numbers. 16 and 25 are squares of 4 and 5, so the irrational number we are looking for must be about halfway between 16 and 25.

$\sqrt{20} =4.472135955$ is more than 4.47 and less than 4.48

5 0

3 years ago