Answer: 8=x+5, x-3=5
Step-by-step explanation: Find the value of ‘x’ by subtracting 5 in the first equation. Add 3 to the second equation.
Answer:
120
Step-by-step explanation:
( sorry thats wrong i see hours)
Answer:
Second one
Step-by-step explanation:
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.
When multiplying numbers, it doesn't matter which number is first or second.
The correct answer is: Commutative Property of Multiplication