Answer:
Lets take all factors into consideration first
The door is a rectangle and the area of a rectangle is length times width
Let the width be w
Let the length be l
Equation length × breadth = area
(w+48)w = 3024
w^2 + 48w = 3024
w^2 + 48w - 3024 = 0
w^2 + 84w - 36w - 3024 = 0
w(w + 84) -36 ( w + 84) = 0
(w + 84) (w - 36) = 0
w + 84 = 0 AND w - 36 =0
w = -84 and w = 36
Since width cannot be negative, the right answer is 36
How did I get 84 and 36? Well, I had to factorize 3024 and since 84 times 36 is 3024 and 84 minus 36 is 48, I chose them.
Count the number of times x is used as a factor of this polynomial. I count 4. Thus, this expression will have 4 zeros.
0.39 inches.
Or 0.4 if you want to round it ;3
Answer:
2/3
Step-by-step explanation:
this is the right answer on ape x
Answer:
A sample of 3851 is required.
Step-by-step explanation:
We have that to find our level, that is the subtraction of 1 by the confidence interval divided by 2. So:
![\alpha = \frac{1 - 0.98}{2} = 0.01](https://tex.z-dn.net/?f=%5Calpha%20%3D%20%5Cfrac%7B1%20-%200.98%7D%7B2%7D%20%3D%200.01)
Now, we have to find z in the Z-table as such z has a p-value of .
That is z with a pvalue of , so Z = 2.327.
Now, find the margin of error M as such
![M = z\frac{\sigma}{\sqrt{n}}](https://tex.z-dn.net/?f=M%20%3D%20z%5Cfrac%7B%5Csigma%7D%7B%5Csqrt%7Bn%7D%7D)
In which
is the standard deviation of the population and n is the size of the sample.
Variance is 5.76 kWh
This means that ![\sigma = \sqrt{5.76} = 2.4](https://tex.z-dn.net/?f=%5Csigma%20%3D%20%5Csqrt%7B5.76%7D%20%3D%202.4)
They would like the estimate to have a maximum error of 0.09 kWh. How large of a sample is required to estimate the mean usage of electricity?
This is n for which M = 0.09. So
![M = z\frac{\sigma}{\sqrt{n}}](https://tex.z-dn.net/?f=M%20%3D%20z%5Cfrac%7B%5Csigma%7D%7B%5Csqrt%7Bn%7D%7D)
![0.09 = 2.327\frac{2.4}{\sqrt{n}}](https://tex.z-dn.net/?f=0.09%20%3D%202.327%5Cfrac%7B2.4%7D%7B%5Csqrt%7Bn%7D%7D)
![0.09\sqrt{n} = 2.327*2.4](https://tex.z-dn.net/?f=0.09%5Csqrt%7Bn%7D%20%3D%202.327%2A2.4)
![\sqrt{n} = \frac{2.327*2.4}{0.09}](https://tex.z-dn.net/?f=%5Csqrt%7Bn%7D%20%3D%20%5Cfrac%7B2.327%2A2.4%7D%7B0.09%7D)
![(\sqrt{n})^2 = (\frac{2.327*2.4}{0.09})^2](https://tex.z-dn.net/?f=%28%5Csqrt%7Bn%7D%29%5E2%20%3D%20%28%5Cfrac%7B2.327%2A2.4%7D%7B0.09%7D%29%5E2)
![n = 3850.6](https://tex.z-dn.net/?f=n%20%3D%203850.6)
Rounding up:
A sample of 3851 is required.