You may need to use the approp Suppose that an accounting firm does a study to determine the time needed to complete one person's tax forms. It randomly surveys 200 people. The sample mean is 22.8 hours. There Is a known population standard deviation of 6.2 hours. The population distribution is assumed to be normal (a) Find the following ()) (11)- (1) (d) Construct a 90% confidence interval for the population mean time to complete the tax forms. (1) State the confidence interval. (Round your answers to two decimal places.) (1) Sketch the graph. (Round your answers to two decimal places.) Figure Description NA C.L.- 32