Consider a class of 30 students. The frequency distribution of their scores on a test is as follows: 10 students scored between 70-79, 8 students scored between 80-89, 6 students scored between 90-99 and 6 students scored between 100-110. What is the percentage frequency of students who scored between 80 and 110?

Step 1 ：First, we find the total number of students who scored between 80 and 110. This is the sum of the students who scored between 80-89, 90-99 and 100-110, which is \(8 + 6 + 6 = 20\) students.

Step 2 ：Next, we calculate the percentage frequency by dividing the number of students who scored between 80 and 110 by the total number of students, and then multiplying the result by 100. This can be represented as \(\frac{20}{30} \times 100 = 66.67\%\)