Niles is making an investment with an expected return of 12% per year and a standard deviation of 4.5% per year. If 90% of the outcomes are contained within 1.645 standard deviations, then what is the range of possible returns (confidence interval) that can be expected to occur 90% of the time? 4.6%to19.4%4.6%to19.4%7.5%to16.5%3.0%to21.0%