Answer:
Step-by-step explanation:
You need to get w on one side by itself.
Start out by subtracting 2l from both sides.
p−2l=2w.
Now since w is being multiplied by 2 we need to divided both sides (all terms) by 2.
w=p2−I
Answer:
You can find 0.5% of a number by multiplying the number by
Step-by-step explanation:
Answer:
a.1.90 years
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

So the correct answer is:
a.1.90 years