单选题
编号：2690458
1. Annual returns on small stocks have a population mean of 12% and a population standard deviation of 20%. If the returns are normally distributed, a 90% confidence interval on mean returns over a 5-year period is:
- A.5.40% to 18.60%
- B.-2.75% to 26.75%
- C.-5.52% to 29.52%