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Suppose that an accounting firm does a study to determine the time needed to complete one person's tax forms. It randomly surveys 100 people. The sample average is 23.8 hours. There is a known population standard deviation of 6.0 hours. The population distribution is assumed to be normal.

  • math -

    cool. what's the question?

  • math -

    how do you Construct a 90% confidence interval for the population average time to complete the tax forms.

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