Answer:
"C" =14
Step-by-step explanation:
14+(-12)=-12+c
-12+c=14+(-12)
-12+c=14-12
-12+c+12=2+12
c=14
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.
Answer:
It does not show variation
Step-by-step explanation:
Given

Required
Determine if there's direct variation between x and y
The general form of direct variation is:

Make y the subject of formula in the given parameters;


Compare
to 
<em>Since they are not of the same form, then the given equation do not show direct variation</em>
Answer:
406
Step-by-step explanation:
6+(4x100)