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.
The reciprocal of 3/8 would be 8/3 (basically reversing the numbers).
When dividing fractions, you can just multiply the first fraction by the reciprocal of the second fraction instead of dividing by the second fraction.
3/4 ÷ 3/8
= 3/4 × 8/3
Simplifying gives us the final answer:
= 2
Let me know if you need any clarifications, thanks!
My answer the question what is the surface area of a triangular prism is 126 yards2
Answer: you would times everything I don’t remember how I did this but I did it by multiplying everything hope I helped and you would add the cm with the answer you got
Answer: 90 degrees
Step-by-step explanation: