Grouped frequency tables are a way of showing data in groups. Set up a new column to write the midpoint of each class. Set up another column to multiply each midpoint by its frequency. Find the sum of ...

There are 30 students, so we are looking for the group which contains the \((30 + 1) \div 2 = 15\frac{1}{2}th\) value, which lies halfway betwen the 15th and the 16th value. The cumulative frequency ...