Answer:
see the photo ............
Answer:
The 90% confidence interval for the average monthly residential water usage for all households in this city is between 4401.3 gallons and 4598.7 gallons.
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
.
So it is z with a pvalue of
, so 
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.

The lower end of the interval is the sample mean subtracted by M. So it is 4500 - 98.7 = 4401.3 gallons
The upper end of the interval is the sample mean added to M. So it is 4500 + 98.7 = 4598.7 gallons
The 90% confidence interval for the average monthly residential water usage for all households in this city is between 4401.3 gallons and 4598.7 gallons.
Hey there!
y-12=20
Add 12 to both sides. (do the inverse of subtraction, which is addition)
y=32
Check answer.
32-12=20 <=== checks out :)
I hope this helps!
~kaikers
Answer:
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Step-by-step explanation:
If there are 20 students, and each team has 5 students, then there will be 4 teams of third graders that will play kickball.
20/5 = 4