Answer:
The margin of error needed to create a 99% confidence interval estimate of the mean of the population is of 0.3547
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.
In this question:

So



The margin of error needed to create a 99% confidence interval estimate of the mean of the population is of 0.3547
c
-
p
I believe
maybe im wrong so you might wanna check with someone else
The answer is C hope this helped you
Answer:
The scientist needs 80 liters of 25% solution and 40 liters of 10% solution.
Step-by-step explanation:
If x is the liters of 25% solution, and y is the liters of 10% solution, then:
x + y = 120
0.25x + 0.10y = 0.20(120)
Solve the system of equations using substitution or elimination. Using substitution:
0.25x + 0.10(120 − x) = 0.20(120)
0.25x + 12 − 0.10x = 24
0.15x = 12
x = 80
y = 40
The scientist needs 80 liters of 25% solution and 40 liters of 10% solution.
1.5/d+34 is the inverse operation