Scientists in Florida are measuring the masses of sea turtles as they hatch. They create a line graph and plot the masses of $18$ turtles. **What is the combined mass, in ounces, of the $3$ lightest turtles?** *The line plot shows the data rounded to the nearest $\dfrac{1}{4}$ ounce.*  [[☃ math-keypad 1]]$\text{ ounces}$