Line Plots · Hard problem

A line plot shows how much trail mix, in cups, each of $10$ hikers brought. Above $\dfrac{1}{4}$ there are $4$ X's, above $\dfrac{1}{2}$ there are $2$ X's, and above $\dfrac{3}{4}$ there are $4$ X's. They pour all the trail mix together and then fill bags that each hold $\dfrac{1}{2}$ cup. How many bags can they fill?