Answer:
= - 2.43%
Step-by-step explanation:
From the information given:
Since the variable (daily returns) is normally distributed, Then, using empirical rule at 95% confidence interval level, we have:

where;
The expected mean daily return 
The standard deviation 
Given that the 95% confidence interval is expected to be a maximum loss, then the probability is left-tailed which is 1.65
away from the average.
Thus the distribution of the lower boundary can be computed as:
= 
= 
= 
= - 2.43%