If you take 0.98 and multiply by 2.5 you get 2.45 so there is no better deal. ☺
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.
Answer: See below
Step-by-step explanation:
The Pythagorean Theorem is a²+b²=c². Since each problem gives us the length of a, b, or c, we can directly plug them into this equation and solve.
Triangle EFG
9²+b²=41²
81+b²=1681
b²=1600
b=√1600
b=40
----------------------------------------------------------------------
Triangle PQR
20²+21²=c²
400+441=c²
c²=841
c=√841
c=29
----------------------------------------------------------------------
Triangle XYZ
a²+24²=25²
a²+576=625
a²=49
a=√49
a=7
Answer:
The graph of the circle is not a function