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.
A linear pair is a pair of angles that form a straight line and are therefore, equal to 180 degrees
3n + 19 + 55 + 33 = 180
3n + 107 = 180
3n = 180 - 107
3n = 73
n = 73/3
so < EFG = 3n + 19 = 3(73/3) + 19 = 73 + 19 = 92
and < GFH = 55 + 33 = 88
The answer is 46.8
Plz mark me Brainly