Answer:
The minimum sample size required to create the specified confidence interval is 2229.
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.
What is the minimum sample size required to create the specified confidence interval
This is n when 





Rounding up
The minimum sample size required to create the specified confidence interval is 2229.
Answer:
18
Step-by-step explanation:
That's definitely an example of exponential decay, since the base (1/2) (also called the "common ratio") is greater than 0 but less than 1.
To get from 8.4 to 10 in multiplication, we need to multiply 8.4 by 10/8.4
That means that if we multiply 30 by 10/8.4 we get the answer
which is 35,714
The same with the other
8.4 times 100/30 = 28