Answer: The mean and standard deviation are 567.2 and 89.88 resp.
Step-by-step explanation:
Since we have given that
For 370 parts per million = 7% = 0.07
For 440 parts per million = 10% = 0.10
For 550 parts per million = 49% = 0.49
For 670 parts per million = 34% = 0.34
So, Mean of the carbon dioxide atmosphere for these trees would be
![E[x]=370\times 0.07+440\times 0.1+550\times 0.49+670\times 0.34=567.2](https://tex.z-dn.net/?f=E%5Bx%5D%3D370%5Ctimes%200.07%2B440%5Ctimes%200.1%2B550%5Ctimes%200.49%2B670%5Ctimes%200.34%3D567.2)
And
![E[x^2]=370^2\times 0.07+440^2\times 0.1+550^2\times 0.49+670^2\times 0.34=329794](https://tex.z-dn.net/?f=E%5Bx%5E2%5D%3D370%5E2%5Ctimes%200.07%2B440%5E2%5Ctimes%200.1%2B550%5E2%5Ctimes%200.49%2B670%5E2%5Ctimes%200.34%3D329794)
So, Variance would be
![Var\ x=E[x^2]-E[x]^2=329794-567.2^2=8078.16](https://tex.z-dn.net/?f=Var%5C%20x%3DE%5Bx%5E2%5D-E%5Bx%5D%5E2%3D329794-567.2%5E2%3D8078.16)
So, the standard deviation would be
Hence, the mean and standard deviation are 567.2 and 89.88 resp.
4. Let the numbers be x - 2, x, and x + 2, where x is an odd number.
2(x² - 4) - 4x = (x + 2)² + 21
2x² - 8 - 4x = x² + 4x + 4 + 21
2x² - 4x - 8 = x² + 4x + 25
x² - 8x - 33 = 0
(x - 11)(x + 3) = 0
x = 11, or -3
When x = 11, x - 2 = 9, x + 2 = 13
When x = -3, x - 2 = -5, x + 2 = -1
Explanation: You are on the right track. However, rather than having three unknown variables, try to reduce your working out to one unknown variable. Since you know they are consecutive odd numbers, you can simply let x be the middle term and the other two be + and - 2, provided x is an odd number.
That will reduce your variable issues, and helps as the first and third provide a difference of two squares, and this works out very nicely.
Q5: is essentially the same process. Let your variables be something in the form of one unknown variable, and you should be okay from there. Let me know if you're stuck.
Hello!
First of all let's find the perimeter (circumference) of the semi circles. We can combine them to make one circle with a diameter of 4 (as we can see the side length of one semi circle is 4 cm. We now plug it into the circumference equation (
=3.14).
4(3.14)=12.56
Now we add up the side lengths of the rectangle.
4+6+4+6=20
Now we add up the length of our circle and rectangle.
20+12.56=32.56
Therefore our answer is
32.56 cm.
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Now to find the area! If we combine the two semicircles, we get a circle with a diameter of four. This means that is has a radius of two. We use the equation below to find the area of the two circles.
A=
r²
First we will square our radius.
2(2)=4
Now we multiply by pi.
4(3.14)=12.56
Now we need to find the area of the rectangle.
6(4)=24
Now we add.
24+12.56=
36.56.
I hope this helps!
15.6/ (-3) = -5.2
hope this helps
Answer:
the tetrahedron has two bases
Step-by-step explanation:
a tetrahedron has only one bases which is a triangle
so this is not true
hope this helps
