It need to be at least 50 ft long and 50 ft wide.
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.
Would this be the correct answer? If not, can you further explain the question?(11x+8y)(11x-8y)
Answer: $15.00
Step-by-step explanation: If 3 sodas cost you $4.50 then you divide it by 3 to get $1.50 per soda. Then you multiply the number by ten to get $15.