The range of a set of data is calculated by subtracting the lowest value from the highest value.

In this case:

• Highest value = 81
• Lowest value = 51

The formula for range is:

$\text{Range} = \text{Highest value} - \text{Lowest value}$

Substituting the given values:

$\text{Range} = 81 - 51 = 30$

So, the range is 30.

Would you like a more detailed explanation or have any further questions?

Related Questions:

1. What is the formula for calculating the range of a data set?
2. How does the range help in understanding the spread of data?
3. What is the difference between range and standard deviation?
4. Can the range be negative?
5. How do outliers affect the range of a data set?

Tip: The range gives you a quick measure of how spread out the data values are, but it doesn't account for the distribution of values in between the highest and lowest points.