Answer:
y =
x + 8
Step-by-step explanation:
the equation of a line in slope intercept form is
y = mx + c ( m is the slope and c the y-intercept )
rearrange 2x + 3y = 9 into this form
subtract 2x from both sides
3y = - 2x + 9 ( divide all terms by 3 )
y = -
x + 3 ← in slope-intercept form
with slope m = - ![\frac{2}{3}](https://tex.z-dn.net/?f=%5Cfrac%7B2%7D%7B3%7D)
given a line with slope m then the slope of a line perpendicular to it is
= -
= -
=
, hence
y =
x + c ← is the partial equation
to find c substitute (- 2, 5) into the partial equation
5 = - 3 + c ⇒ c = 5 + 3 = 8
y =
x + 8 ← equation of perpendicular line
1)Option B is the correct option.
231
2)Option A is the correct option.
6336
3)Option B is the correct option.
307 (not sure)
3:4 because both numbers can be divided by 3
X + 2 > 3x - 8
subtract x from both sides
2 > 2x - 8
add 8 to both sides
10 > 2x
divide both sides by 2
5 > x
ANSWER: 5 > x
Hope this helps! :)
Answer:
A sample of 179 is needed.
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 - 0.85}{2} = 0.075](https://tex.z-dn.net/?f=%5Calpha%20%3D%20%5Cfrac%7B1%20-%200.85%7D%7B2%7D%20%3D%200.075)
Now, we have to find z in the Ztable as such z has a pvalue of
.
That is z with a pvalue of
, so Z = 1.44.
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.
A previous study found that for an average family the variance is 1.69 gallon?
This means that ![\sigma = \sqrt{1.69} = 1.3](https://tex.z-dn.net/?f=%5Csigma%20%3D%20%5Csqrt%7B1.69%7D%20%3D%201.3)
If they are using a 85% level of confidence, how large of a sample is required to estimate the mean usage of water?
A sample of n is needed, and n is found for M = 0.14. 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)
![0.14 = 1.44\frac{1.3}{\sqrt{n}}](https://tex.z-dn.net/?f=0.14%20%3D%201.44%5Cfrac%7B1.3%7D%7B%5Csqrt%7Bn%7D%7D)
![0.14\sqrt{n} = 1.44*1.3](https://tex.z-dn.net/?f=0.14%5Csqrt%7Bn%7D%20%3D%201.44%2A1.3)
![\sqrt{n} = \frac{1.44*1.3}{0.14}](https://tex.z-dn.net/?f=%5Csqrt%7Bn%7D%20%3D%20%5Cfrac%7B1.44%2A1.3%7D%7B0.14%7D)
![(\sqrt{n})^2 = (\frac{1.44*1.3}{0.14})^2](https://tex.z-dn.net/?f=%28%5Csqrt%7Bn%7D%29%5E2%20%3D%20%28%5Cfrac%7B1.44%2A1.3%7D%7B0.14%7D%29%5E2)
![n = 178.8](https://tex.z-dn.net/?f=n%20%3D%20178.8)
Rounding up
A sample of 179 is needed.