Answer:
(a) Margin of error ( E) = $2,000 , n = 54
(b) Margin of error ( E) = $1,000 , n = 216
(c) Margin of error ( E) = $500 , n= 864
Step-by-step explanation:
Given -
Standard deviation
= $7,500
= 1 - confidence interval = 1 - .95 = .05
=
= 1.96
let sample size is n
(a) Margin of error ( E) = $2,000
Margin of error ( E) = 
E = 
Squaring both side


n = 54.0225
n = 54 ( approximately)
(b) Margin of error ( E) = $1,000
E = 
1000 = 
Squaring both side


n = 216
(c) Margin of error ( E) = $500
E = 
500 = 
Squaring both side


n = 864
Answer:
The answer is b sorry if its wrong
Step-by-step explanation:
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In this problem, we need to plug in the given x values for

and find a and b.
When we plug in 1, we get:

Simplify:



We got our first statement about the values of the variables. If we find one more we can find those 2 variables.
We have another given root: 4.
Plug it in:




Now we have our second one. We can combine them:

I use elimination method which is easier here.
Multiply the top equation by -1:

Add them up:

Simplify:

Now we have a, we can plug in one of those equations to find b:



So, the answers are

and

.