The calculations for the given expense data are as follows:

• Mean ($\overline{x}$): $348.00$
• Variance ($s^2$): $241.60$
• Standard Deviation ($s$): $15.543$

Would you like further details or have any questions?

Here are five related questions for further exploration:

1. How does the standard deviation help in understanding the variation in the expenses?
2. What is the significance of using $s^2$ (sample variance) versus population variance?
3. How would the results differ if the sample size was larger?
4. Can you use this data to predict future expenses?
5. What are some other cost-control strategies a company could use based on statistical analysis?

Tip: The standard deviation gives you an idea of how much the values in your data set differ from the mean, helping you assess variability.