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3 years ago

140/100 simplified as a fraction

Mathematics

2 answers:

Jet001 [13]3 years ago

4 0

Answer:7/5

Step-by-step explanation:

140/100 = 7/5 = 1 2/5

Mumz [18]3 years ago

4 0

Answer:7/5

Step-by-step explanation:

140/100=14/10=7/5

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Which data set is the farthest from a normal distribution?

Trava [24]

Answer:

i belive its c

Step-by-step explanation:

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3 years ago

Read 2 more answers

An experiment was conducted to observe the effect of an increase in temperature on the potency of an antibiotic. Three 1-ounce p

ludmilkaskok [199]

Answer:

a) $y=-0.317 x +46.02$

b) Figure attached

c) $S^2=\hat \sigma^2=MSE=\frac{190.33}{10}=19.03$

Step-by-step explanation:

We assume that th data is this one:

x: 30, 30, 30, 50, 50, 50, 70,70, 70,90,90,90

y: 38, 43, 29, 32, 26, 33, 19, 27, 23, 14, 19, 21.

a) Find the least-squares line appropriate for this data.

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

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

Where:

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

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

So we can find the sums like this:

$\sum_{i=1}^n x_i = 30+30+30+50+50+50+70+70+70+90+90+90=720$

$\sum_{i=1}^n y_i =38+43+29+32+26+33+19+27+23+14+19+21=324$

$\sum_{i=1}^n x^2_i =30^2+30^2+30^2+50^2+50^2+50^2+70^2+70^2+70^2+90^2+90^2+90^2=49200$

$\sum_{i=1}^n y^2_i =38^2+43^2+29^2+32^2+26^2+33^2+19^2+27^2+23^2+14^2+19^2+21^2=9540$

$\sum_{i=1}^n x_i y_i =30*38+30*43+30*29+50*32+50*26+50*33+70*19+70*27+70*23+90*14+90*19+90*21=17540$

With these we can find the sums:

$S_{xx}=\sum_{i=1}^n x^2_i -\frac{(\sum_{i=1}^n x_i)^2}{n}=49200-\frac{720^2}{12}=6000$

$S_{xy}=\sum_{i=1}^n x_i y_i -\frac{(\sum_{i=1}^n x_i)(\sum_{i=1}^n y_i)}=17540-\frac{720*324}{12}{12}=-1900$

And the slope would be:

$m=-\frac{1900}{6000}=-0.317$

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

$\bar x= \frac{\sum x_i}{n}=\frac{720}{12}=60$

$\bar y= \frac{\sum y_i}{n}=\frac{324}{12}=27$

And we can find the intercept using this:

$b=\bar y -m \bar x=27-(-0.317*60)=46.02$

So the line would be given by:

$y=-0.317 x +46.02$

b) Plot the points and graph the line as a check on your calculations.

For this case we can use excel and we got the figure attached as the result.

c) Calculate S^2

In oder to calculate S^2 we need to calculate the MSE, or the mean square error. And is given by this formula:

$MSE=\frac{SSE}{df_{E}}$

The degred of freedom for the error are given by:

$df_{E}=n-2=12-2=10$

We can calculate:

$S_{y}=\sum_{i=1}^n y^2_i -\frac{(\sum_{i=1}^n y_i)^2}{n}=9540-\frac{324^2}{12}=792$

And now we can calculate the sum of squares for the regression given by:

$SSR=\frac{S^2_{xy}}{S_{xx}}=\frac{(-1900)^2}{6000}=601.67$

We have that SST= SSR+SSE, and then SSE=SST-SSR= 792-601.67=190.33[/tex]

So then :

$S^2=\hat \sigma^2=MSE=\frac{190.33}{10}=19.03$

5 0

3 years ago

-4.8=1.2s+2s+4<br><br><br>Please help me <br>

nikdorinn [45]

Simplify both sides of the equation
-4.8=1.2s+2s+4
Combine like terms
-4.8=(1.2s+2s)+(4)
-4.8=3.2s+4
Flip the equation
3.2s+4=-4.8
Subtract both sides by 4
3.2s+4-4=-4.8-4
3.2s=-8.8
Divide both sides by 3.2
3.2s/3.2= -8.8/3.2
S=-2.75 will be the answer hope it helps

6 0

3 years ago

WILL MARK BRAINLIEST! Bill is in a class of 15 boys and 35 girls. 40% of the students in the class take the bus to school. How m

Studentka2010 [4]

Answer:

30 students

Step-by-step explanation:

all students = girls+boys

all students= 15+35=50

40% of 50= 20

50-20=30

30 students didn't take the bus to school

4 0

3 years ago

Read 2 more answers

n^2-2n-3 where n is the number of key rings in thousands, find the number of key rings sold when the profits is $5,000

ArbitrLikvidat [17]

Answer:

For the profit of $5,000, the key chains made is n = 4,000.

Step-by-step explanation:

Here the given expression , where: n = Number of key rings in thousands is given as:

P(n) = n²- 2 n - 3

Now, Profit is given to be $5,000.

Also, as we know 5000 = 5 x (1,000)

⇒ n²- 2 n - 3 = 5

Now, solving the above expression for the value of n, we get:

$n^2 - 2 n - 3 = 5\\\implies n^2 -2n - 8 = 0\\\implies n^2 -4n + 2n - 8 = 0\\\implies n(n-4) + 2(n-4) = 0\\\implies (n-4) (n+2) = 0$

So, n = 4, OR , n = -2

Now, as n = The number of key chains. So it CANNOT BE NEGATIVE.

So, n= 4 = 4 x (1,000) = 4,000 key rings.

Hence, for the profit of $5,000, the key chains made is n = 4,000.

8 0

3 years ago