For a simple random sample of size 4761, the margin of error for 95 percent confidence is about:
A) ± 0.0145%.
B) ± 1.45%.
C) ± 0.021%.
D) ± 0.00021%.

Question

Quizplus · Accepted Answer

The formula for the margin of error is: 
margin of error = z* (standard deviation / sqrt(sample size))
For a 95% confidence interval, the z-value is 1.96.
Since the sample size is very large (n=4761), we can assume that the standard deviation is equal to the population standard deviation (or use a conservative estimate for the standard deviation).

Therefore, the margin of error is approximately: 
1.96 * (standard deviation / sqrt(sample size)) 
= 1.96 * (1 / sqrt(4761)) 
= 1.45%
So the best choice is B, ±1.45%.

For a Simple Random Sample of Size 4761, the Margin