Annual salary plus bonus data for chief executive officers are presented in the BusinessWeek Annual Pay Survey. A preliminary sa
mple showed that the standard deviation is $675 with data provided in thousands of dollars. How many chief executive officers should be in a sample if we want to estimate the population mean annual salary plus bonus with a margin of error of $100,000? (Note: The desired margin of error would be E=100 if the data are in thousands of dollars.) Use 95% confidence.
The sample size n in<em> Simple Random Sampling</em> is given by
<em>
where z = 1.96 is the z-score associated with a 95% confidence level ans s the standard deviation.
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Replacing values
So, there should be 175 chief executive officers in a sample if we want to estimate the population mean annual salary plus bonus with a margin of error of $100,000