Answer:
its B
Step-by-step explanation:
There is normally a shape or something to these problems
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.
Answer:
67
Step-by-step explanation:
The angle with x in it is a vertical angle to the other one labeled & the right angle put together.
Therefore:
48 + 90 = 2x + 4
Solve for x:
138 = 2x + 4
138 - 4 = 2x + (4-4)
134 = 2x
134/2 = 2x/2
X = 67
Hope this helps! Have a great day!