Answer:
a
Step-by-step explanation:
21.12 is 25.6% of 82.5. I hope this helps. :)
-3(-4y+3) +7y
Expand
12y-9+7y
Add like terms
19y-9
First isolate the "y" in the equation.
2y - x = -12 Add x on both sides
2y - x + x = -12 + x
2y = -12 + x Divide 2 on both sides to get "y" by itself


Your slope is
.
For the equation of the line to be parallel to the given equation, the slopes have to be the same. So the parallel line's slope is also 
y = mx + b

To find "b", you plug in the point (18,2) into the equation


2 = 9 + b Subtract 9 on both sides
2 - 9 = 9 - 9 + b
-7 = b
Your equation is:

Answer + Step-by-step explanation:
(a)
Check the attached image.
(b)
Range of sample means : 7.5 - 5.75 = 1.25
(c)
The closer the range of the sample means is to 0 ,
the more confident they can be in their estimate . 
The farther the range of the sample means is from 0 ,
the more confident they can be in their estimate .
The mean of the sample means will tend to be a better estimate
than a single sample mean . 
A single sample mean will tend to be a better estimate
than the mean of the sample means .