Confidence Interval question

guest1174

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Hello this was a home work question I got wrong and I could not figure out how to get the correct answer.

Examining Uniform Crime Reports from 1982 to 2001, the average rate of forcible rape per 100,000 in Anchorage, Alaska, was 82.01 (s = 14.49) while the average rate in the United States was 39.95 (s = 3.27; UCR data).

Construct 99% confidence intervals for each average rate.


Anyone know how to figure out what n is supposed to be so I can fill in the formula and show how you did it. I know the formula is x-bar + or - Z score * (s/sqrt(n-1)) so 82.01 + or - 2.58 (14.49/sqrt(n-1)) but don't know what n is supposed to be in the formula or how to calculate it.
 
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Hello this was a home work question I got wrong and I could not figure out how to get the correct answer.

Examining Uniform Crime Reports from 1982 to 2001, the average rate of forcible rape per 100,000 in Anchorage, Alaska, was 82.01 (s = 14.49) while the average rate in the United States was 39.95 (s = 3.27; UCR data).

Construct 99% confidence intervals for each average rate.


Anyone know how to figure out what n is supposed to be so I can fill in the formula and show how you did it. I know the formula is x-bar + or - Z score * (s/sqrt(n-1)) so 82.01 + or - 2.58 (14.49/sqrt(n-1)) but don't know what n is supposed to be in the formula or how to calculate it.
You are already given sigma, so you don't need to calculate it using sqrt(n-1). Your formula should just be

\(\displaystyle \bar{x} ± z×\sigma \)

Can you get z ok for the 99% interval (double ended)?
 
You are already given sigma, so you don't need to calculate it using sqrt(n-1). Your formula should just be

\(\displaystyle \bar{x} ± z×\sigma \)

Can you get z ok for the 99% interval (double ended)?

I am only given s which is the sample standard deviation, not population standard deviation

Do you know how to find the N?

[FONT=Verdana, Arial, Tahoma, Calibri, Geneva, sans-serif]
Brutal topic for a math problem.
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[FONT=Verdana, Arial, Tahoma, Calibri, Geneva, sans-serif]This is from a criminal justice course on statistics[/FONT]
 
I am only given s which is the sample standard deviation, not population standard deviation

Do you know how to find the N?

This is from a criminal justice course on statistics
Since the data are taken from the UCRs for 1982-2001, it would appear N = 20.
 
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