A retail chain believes that the average age of its customers, nationwide, is 22.4 years, with a variance of 3.2 years. A researcher draws a sample of 32 customers from a single store to compare the age of its customers to the nationwide average. If she is conducting a two-tailed test with an alpha level of 0.05, what are the lower and upper critical values for the sample mean? 0 22.36 and 25.63 0 21.23 and 24.56 0 21.21 and 23.50 0 21.21 and 21.65