Answer:
y=-1/4x+8
Step-by-step explanation:
To find the equation of a line that is perpendicular to a line, you would take the opposite reciprocal of the slope.
Before that, we need to change the equation into slope-intercept form.
-4x+y=10
y=4x+10
The opposite reciprocal of the slope is -1/4.
Now, let's use the point-slope formula to find our equation of the line that passes through (-4,9).
y-y1=m(x-x1)
y-9=-1/4(x-(-4))
y-9=-1/4x-1
y=-1/4x+8
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:
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
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 
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
Rounding up
A sample of 179 is needed.
I’m not sure if the 15 is the question number but if it is the answer is 32. use PEMDAS
