The sample standard deviation of the given data $[28, 13, 30, 18, 21, 24, 19]$ is approximately 5.93, rounded to two decimal places.

Would you like further details on how this was calculated, or do you have any other questions?

Here are 5 related questions you might find useful:

1. How do you calculate the variance of a sample data set?
2. What is the difference between sample and population standard deviation?
3. How does increasing or decreasing a data point affect the standard deviation?
4. Can standard deviation ever be negative? Why or why not?
5. How do you interpret standard deviation in real-world problems?

Tip: Always make sure to distinguish between sample and population standard deviations, especially when dealing with real-world data!