Problem N5627 probability theory confidence interval

Problem N5627 probability theory confidence interval

5627. In the order of random re-sampling, a survey of 400 workers of a certain enterprise was carried out, as a result of which it was found that the average wage of workers is 7,000 rubles. Determine with reliability 0.9544 the possible limits of workers´ wages, assuming the distribution of workers´ wages to be normal with a mean square deviation of 180 rubles.

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Detailed solution. Decorated in Microsoft Word 2003 (Quest decided to use the formula editor)