A stock's returns are normally distributed with a mean of 8% pa and a standard deviation of 15 percentage points pa. What is the 99% confidence interval of returns over the next year? Note that the Z-statistic corresponding to a one-tail:
- 90% normal probability density function is 1.282.
- 95% normal probability density function is 1.645.
- 97.5% normal probability density function is 1.960.
- 99% normal probability density function is 2.326.
- 99.5% normal probability density function is 2.576
The 99% confidence interval of annual returns is between: