Answer: 3.0%

## Explanation The standard deviation of the mean (also known as the standard error) is calculated using the formula: \[ \text{Standard Error} = \frac{\sigma}{\sqrt{n}} \] Where: - \(\sigma\) = population standard deviation = 15% - \(n\) = sample size = 25 Substituting the values: \[ \text{Standard Error} = \frac{15\%}{\sqrt{25}} = \frac{15\%}{5} = 3.0\% \] **Key Points:** - The standard error measures the variability of the sample mean around the population mean - It decreases as the sample size increases (due to the square root in the denominator) - The mean weekly return of 7% is not used in this calculation, as we're only concerned with the variability of the mean, not its value - This is a fundamental concept in statistics and is particularly important in risk management for understanding the precision of estimated parameters

Author: LeetQuiz .