A) 3(a - b) = 3*a +3*-b = 3a - 3b EQUAL
b) 2a(2 + b) = 4a + 2ab NOT EQUAL
Answer:
c) .22
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:

Then



Answer:
d
Step-by-step explanation:
I already did this before
The ratio is 3:2, hope it helps