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[大學]Statistics

發表 cynthiawong123 於 星期五 十月 04, 2013 12:54 am

A statistician conducted a research and theresults showed that 65% of blue-collar workers agree that 8 working hours perday is acceptable. A random sample of n blue-collar workers was selected andlet X be a random variable defined as the number of blue-collar workers agreethe view.

(a)What is the minimum value of n such thatX can be approximated by the normal random variable? Using this value of n,find the mean and standard deviation of the sampling distribution of the sampleproportion.

(b) Based on the results of (a), find theprobability that less than half of the blue-collar workers agree the view.


(c) A statistician conducted the sameresearch for a random sample of 200 white-collar workers. It was found that 150of them agree the view. Find the 97.5% confidence interval for the populationproportion of white-collar workers who agree that 8 working hours per day isacceptable.



Thank you.