Answer:
A sample of 217 is needed.
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.
If the population standard deviation is $3,750 how large should the sample be if margin of error is $500
We have that 
.
We need a sample of n, and n is found when 
. So
Rounding up
A sample of 217 is needed.
The first step to solving this is to collect the like terms in this equation,, which are all the numbers with an x variable attached to them.
8.5x = -25.5
Now all you need to do to find x is divide both sides of the equation by 8.5
x = -3
This means that in order to make this equation true,, x must be -3.
Let me know if you have any further questions
:)
A) The equation will become: 18.50 (1.005) + 18.50 (0.04)= 19.3325
Which can be rounded to 19.33
b) 18.50 (1.04)-18.50(1.005)= 0.6475
Which can be rounded to 0.65
Therefore your answer is Number 1)
sry my mistake wrong quesrion
