Well, 625 is 5 x 5 x 5 x 5 .
So that would be:
(5)⁴
5 x (5)³
(5)² x (5)²
And you could even go the other way if you want to get silly:
(5)⁵ x (5)⁻¹
(5)⁶ x (5)⁻²
.
.
etc.
Answer:
The 95% confidence interval for the population mean is between 61.5 and 68.5.
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 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 65 - 3.5 = 61.5
The upper end of the interval is the sample mean added to M. So it is 65 + 3.5 = 68.5
The 95% confidence interval for the population mean is between 61.5 and 68.5.
2x-y=3
use the substitution method
2(2)-y= 3
4-y= 3
move 4 to the other side
sign changes from +4 to -4
4-4-y= 3-4
-y= 3-4
-y=-1
mutiply both sides by -1 to get +y
(-1)(-y)= (-1)(-1)
y= (-1)(-1)
Answer: y= 1