To find the range of a set of data, we need to determine the difference between the highest and lowest values in the set. Here are the steps to calculate the range of the given marks:
1. Identify the Maximum Mark:
- From the list of marks \(\{21, 20, 25, 5, 10, 15, 30, 12, 7, 16, 9, 22\}\), the highest mark is \(30\).
2. Identify the Minimum Mark:
- From the same list, the lowest mark is \(5\).
3. Calculate the Range:
- The range is found by subtracting the minimum mark from the maximum mark:
[tex]\[
\text{Range} = \text{Maximum Mark} - \text{Minimum Mark}
\][/tex]
- Substituting in the given values:
[tex]\[
\text{Range} = 30 - 5 = 25
\][/tex]
Therefore, the range of the marks obtained by the students is [tex]\(25\)[/tex].