Suppose that an accounting firm does a study to determine the time needed to complete one person's tax forms. It randomly surveys 125 people. The sample average is 23.1 hours. There is a known population standard deviation of 6.0 hours. The population distribution is assumed to be normal. NOTE: If you are using a Student's t-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 average time to complete the tax forms. (i) State the confidence interval. (Round your answers to two decimal places.) ( x,| x) (ii) Sketch the graph. 0.05 y Z: v c_L_=:x 2 NIQ n :X E): ..(lil),CaLculat.e the error bound. (Round your answer to two decimal places.) >