You plan to conduct a survey to find what proportion of the

You plan to conduct a survey to find what proportion of the workforce has two or more jobs. You decide on the 98 percent confidence level and state that the estimated proportion must be within 3 percent of the population proportion. A pilot survey reveals that 8 of the 48 sampled hold two or more jobs. How many in the workforce should be interviewed to meet your requirement?

Solution

You plan to conduct a survey to find what proportion of the workforce has two or more jobs.
You decide on the 98 percent confidence level and state that the estimated proportion must be within 2 percent of the population proportion.
A pilot survey reveals that 8 of the 48 sampled hold two or more jobs. How many in the workforce should be interviewed to meet your requirements?
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z value at 98% confidence level = 2.33

n = [z/E]^2 *pq
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n = [2.33/0.03]^2*(1/6)(5/6)

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n = 838 when rounded up