In a survey conducted by a business management company 51 of

In a survey conducted by a business management company, 51% of the U.S. workers siad they have negotiated a pay raise at least once inthier lives. The sample size used in the study was not disclosed.

A) Suppose that the survey had a sample size of n=500. Construct a condifidence interval estimate for the proportion of all United States workers who have negotiated a pay raise.

Solution

Answer to the question)

P = 0.51

n = 500

Standard error SE = srt(0.51 *0.49/500)

SE = 0.0224

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Let the confidence level = 95% , so the Z critical value = 1.96

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The formula of cofndience interval is:

p - z* SE , p + z * SE

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On plugging the values we get

0.51 - 1.96 *0.0224 , 0.51 +1.96 *0.0224

0.04661 , 0.5539