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.
B would be correct the -3 x and 3 x cancel out
Answer:
Step-by-step explanation:
h(x)=44x+8-(30x+15)
=44x+8-30x-15
=44x-30x+8-15
=14x-7
Answer:
You divide by - 1
Step-by-step explanation:
-x divided by - 1 is x
5 divided by - 1 is - 5
x > - 5