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2 years ago

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What is the answer to Becky you used 1/3 yards of ribbon to tie a package and 1/6 yards of ribbon to tie a bow how many yards of

ribbon did Becky use

1 answer:

olya-2409 [2.1K]2 years ago

5 0

Answer: Becky used 1/2 yards of ribbon

Step-by-step explanation:

1/3=2/6

so 2/6 + 1/6 = 3/6 then simplify

1/2

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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

2 years ago

Try This question solve using elimination I’ll give you brainliest

koban [17]

Answer:

(7, 1/2)

Step-by-step explanation:

Multiply second equation by 2 and subtract.

3x - 4y = 19

- (4x - 4y = 26)

You get -x = -7

x = 7

Substitute x into any equation.

3(7) - 4y = 19

21 - 4y = 19

-4y = -2

y = 1/2

4 0

3 years ago

Use the balanced scale to find the conversion factor that can be used to convert the number of blocks to the weight of the block

marusya05 [52]

Answer:

the answer is 24 lb

i think

Stepkby-step explanation:

it is 24 because it is 6 1lb blocks x 4 will give you 24

4 0

2 years ago

Read 2 more answers

which sequence uses the algebraic expression 4n+5 to describe the relationship between a term in the sequence and its position,

Veronika [31]

Is there any enquations

3 0

2 years ago

A circle is inscribed in a square. A point in the figure is selected at random. Find the probability that the point will be in t

hram777 [196]

P of selecting point on the shaded region = shaded area/whole area
<span>P( selecting point on the shaded ) = ( the four shaded circles ) / the whole square </span>
<span>P of selecting point on the shaded = ( 4 * ( π * r^2 ) )/ x^2 </span>
<span>P of selecting point on the shaded = ( 4 * ( π * (x/4)^2 ) )/ x^2 </span>
<span>P of selecting point on the shaded = ( 4 * ( π * x^2/16 ) )/ x^2 </span>
<span>P of selecting point on the shaded = ( π * x^2/4 )/ x^2 </span>
<span>P of selecting point on the shaded = x^2( π/4 )/ x^2 </span>
<span>P( selecting point on the shaded ) = π/4 ≈ 0.7854 ≈ 79%
=80%
D is right option hope this helps</span>

4 0

3 years ago