1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
anyanavicka [17]
3 years ago
9

Show that the value of the expression: ( 10+5 3 + 10−5 3 )2 is a rational number.

Mathematics
1 answer:
Oxana [17]3 years ago
7 0

Answer:

The value of the expression is 400

You might be interested in
Can someone please help ASAP?!!!
Lostsunrise [7]

Answer:

Step-by-step explanation:

4 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

5 0
3 years ago
Describe the locus in space.
yanalaym [24]

Answer: an endless cylinder with radius 4 mm and centerline

8 0
3 years ago
If a coin has been altered so that the probability of heads coming up is 3/10, then the probability of tails coming up is also 3
soldier1979 [14.2K]
False. In a coin, there are 2 possible out comes i.e. a head and a tail. if p is the probability of one side coming up, then the probability of the other side comin up will be q = 1 - p.

Therefore, if the probability of head coming up is 3/10, the probability of tail coming up will be 1 - 3/10 = 7/10.
8 0
3 years ago
The number 6 has exactly four different factors:1,2,3 and 6. How many different factors does the number 36 have?
Aliun [14]
36 has 1,2,3,4,6,and 9

3 0
3 years ago
Read 2 more answers
Other questions:
  • I need help on this please asap.
    15·2 answers
  • Helpppppppppppppppppp
    14·1 answer
  • when have you calculated the mean in real life? and do you always have to use math in order to find the mean?
    11·1 answer
  • If x = 45, y = 63, and the measure of AC = 4 units, what is the difference in length between segments AB and AD? Round your answ
    13·1 answer
  • A juice box has 20% more juice in its new package the original package held 12 ounces of juice how much juice does the new packa
    11·1 answer
  • Which quadrant contains the point named by (4, -8) sorry i’m rly bad at this!!, 20 pts!
    5·2 answers
  • What is the quotient when 1.272 divided by 0.003?
    8·2 answers
  • Juan has a cellular phone that costs $12.95 per month plus 25¢ per minute for each call. Tiffany has a cellular phone that costs
    13·1 answer
  • A cheque recevied from ram 3400 in full settlement of 3500 journal entry​
    13·1 answer
  • What is 9 + 10 because I might be so.
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!