Answer:
a = 18
Step-by-step explanation:
2(a-7)=a+4
Distribute 2 into left side: 2a -14 = a + 4
subtract a from both sides 2a-a-14 = a+4-a
Simplify: a - 14 = 4
Add 14 to both sides: a - 14 + 14 = 4 +14
Simplify: a = 18
If wanted, plug a into original to double check work:
plug in: 2 (18-7) = 18+4
do parenthesis first: 2 (11) = 18+4
do multiplication : 22 = 18+4
additions: 22 =22
a = 18 is correct.
Answer:
The margin of of error for a 95% confidence interval for the population mean is of 1.39 years.
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 = 1.96.
The margin of error is:

In which
is the standard deviation of the population and n is the size of the sample.
Population standard deviation of 3 years
This means that 
Sample of 18 voters
This means that 
Margin of error:



The margin of of error for a 95% confidence interval for the population mean is of 1.39 years.
1. 0.5625
2. 144
3. -2
4. -16
Answer:
Step-by-step explanation:
y=mx+b
m is slope
b is y-intercept
slope is 9/10
y-intercept is 1
Answer:
x = 74
Step-by-step explanation:
2 * x + 19 = 167
2x + 19 = 167
So we have to subtract 19 from both sides
2x = 148
Divide both sides by 2
x = 74