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3 years ago

The temperature at 6:00 P.M. was 3°C. At midnight, the temperature was -2°C.

Mathematics

1 answer:

aliina [53]3 years ago

5 0

Answer:

-5 degrees

Step-by-step explanation:

In this scenario, since the final temperature was the temperature that existed at midnight then that value is subtracted from the initial temperature which was at 6:00 PM. Therefore we do the following calculation...

(-2) - 3 = x

-5 = x

Finally, we can see that there was a change in temperature of -5 degrees between 6:00 P.M. and Midnight. Meaning that the temperature during this time dropped a total of 5 degrees. Since, real numbers include negatives then the answer to this question is -5 degrees

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Sixteen more than twice a number,m, is 36. write an equation and solve to find the number.

Dimas [21]

32m=36
m=36/32
m=9/8
that's the correct answer

3 0

3 years ago

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 :

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

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3 years ago

You are putting together a single elimination tournament. You have 4368 people sign up to compete. How many game will have to be

frosja888 [35]

Answer:

you will have to have 2,184 games to have a winner

Step-by-step explanation:

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4 years ago

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Levart [38]

Answer: 7

Step-by-step explanation: its correct, trust me

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3 years ago

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Find the greatest common factor of the following monomials 26n5 12n2

Sidana [21]

The greatest common factor is 2 $n^{2}$

We first have to look for the largest number that goes into both equations. The factors of 12 are 1, 2, 3, 4, 6 and 12. None of 3, 4, 6, or 12 go into 26 evenly. So 2 is the largest number you can take out.

With the variables, we take out as many as the lowest number will let us. Since the smallest number of n's is 2 in the second term, we take that many.

8 0

3 years ago