Course question

For each investment class in Table 3, assume that future returns are normally distributed with the population mean and standard deviation as given. Based on this assumption:

1. For each investment class, find the probability of a return that is less than zero (that is, find the probability of a loss). Is your answer reasonable for all investment classes? Explain. 
2. For each investment class, find the probability of a return that is: 
   1. Greater than 5%.
   2. Greater than 10%. 
   3. Greater than 20%. 
   4. Greater than 50%. 
3. For which investment classes is the probability of the return greater than 50% is essentially zero? For which investment classes is the probability of such a return greater than 1 percent? Greater than 5%? 
4. For which investment classes is the probability of loss essentially zero? 
5. For which investment classes is the probability of loss greater than 1%? Greater than 10%? Greater than 20%?