Suppose that an accounting firm does a study to determine the time needed to complete one person's tax forms. It randomly surveys125people. The sample mean is23.4hours. There is a known population standard deviation of6.2hours. The population distribution is assumed to be normal.

NOTE: If you are using a Student'st-distribution, you may assume that the underlying population is normally distributed. (In general, you must first prove that assumption, though.)

Construct a 90% confidence interval for the population mean time to complete the tax forms.

(i) State the confidence interval. (Round your answers to two decimal places.)

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(ii) Sketch the graph. (Round your answers to two decimal places.)

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