# Calculating the sample size given confidence levels and standard deviation.

A researcher is interested in estimating the average salary of police officers in a large city. She wants to be 95% confident that her estimate is correct. If the standard deviation is $1050, how large a sample is needed to get the desired information and to be accurate within $200?

Â© BrainMass Inc. brainmass.com March 4, 2021, 5:38 pm ad1c9bdddfhttps://brainmass.com/statistics/confidence-interval/calculating-the-sample-size-given-confidence-levels-and-standard-deviation-3842

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We can simply assume N samples are needed to have the confidence interval of 200 (which is actually two-tailed as ...

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The solution addresses a researcher is interested in estimating the average salary of police officers in a large city. She wants to be 95% confident that her estimate is correct. If the standard deviation is $1050, how large a sample is needed to get the desired information and to be accurate within $200?

$2.49