To solve this equation we must first plug in 5 for x.

<span> (5 - 4x)
</span>↓

(5 - 4 · 5)
The next step would be to multiply 4 by 5 to get rid of the parenthesis within our main parenthesis.

(5 - 4 · 5)

(5 - 20)
The next step would be to subtract both of the numbers within the parenthesis.

(-15)
Now we must multiply.
-

· 15 = -

-

Now we simplify our answer to get our final answer.
-5
Answer:
The 90% confidence interval for the mean time required by all college graduates is between 5.36 years and 5.44 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
.
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 5.4 - 0.04 = 5.36 years.
The upper end of the interval is the sample mean added to M. So it is 5.4 + 0.04 = 5.44 years.
The 90% confidence interval for the mean time required by all college graduates is between 5.36 years and 5.44 years.
37 + x = 2(14 + x)
Explanation:


subtract both sides by 28
9 + x = 2x
subtract both sides by x
9 = x