Answer:
189 components must be sampled.
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 = 2.575.
Now, find the margin of error M as such

Assume that component lifetimes are normally distributed with population standard deviation of 16 hours.
This means that 
How many components must be sampled so that a 99% confidence interval will have margin of error of 3 hours?
n components must be sampled.
n is found when M = 3. So






Rounding up:
189 components must be sampled.
X=y+3
<span>-5x-4y=<span>30
-------------------
Substitute y + 3 for x in </span></span>-5x-4y=30
<span><span>-5<span>(y+3)-</span></span>4y</span>=<span>30
</span>-9y-15=<span>30
</span>----------------------------
Add 15 to each side
<span><span>-9y-15</span>+15</span>=<span>30+<span>15
-9y = 45
</span></span>-----------------------------------
Divide each side by -9
-9y ÷ -9 = 45 ÷ -9
y = -5
Now we solve for x
====================================================================
Substitute -5 for y in x = y + 3
x=-<span><span>5</span>+<span>3
</span></span>x = -2
----------------------
(-2,-5) is your answer
If function and inverse be

Both will seem to be opposite and similar .
Look at the first one
It is showing like 1 is function and other one is its inverse(Attachment )
Hence 1st one is the answer
It is 3 is equivalent of y=2(x+3)^2+5