An economist wants to estimate the mean per capita income (in thousands of dollars) for a major city in California. Suppose that the mean income is found to be $21.1 for a random sample of 717 people. Assume the population standard deviation is known to be $12.6. Construct the 99% confidence interval for the mean per capita income in thousands of dollars. Round your answers to one decimal place. 19.5 to 22.8 19.9 to 22.1 20.4 to 21.8 O 19.2 to 20.1