For the data set $5, 6, 2, 3, 1, 7, 4, 8$:

1. The mean (average) is $4.5$.
2. The variance is $5.25$, which is closest to option b. 5 for question 7.

Would you like further details or have any questions?

Here are 5 related questions for you:

1. How is the mean calculated from a set of numbers?
2. What is the difference between population variance and sample variance?
3. How does the mean affect the calculation of variance?
4. Why is variance important in statistics?
5. Can variance ever be negative?

Tip: When calculating variance, ensure whether it's for a sample or population, as this affects the formula.