To find out how many ounces of romaine lettuce are in a 64-ounce container of salad mix, you can use the percentage of romaine lettuce given in the pie chart.
Romaine lettuce makes up 27% of the salad mix. You can calculate the amount of romaine lettuce by taking 27% of 64 ounces.
\[ \text{Amount of romaine} = 0.27 \times 64 , \text{ounces} \]
Calculating that:
\[ 0.27 \times 64 = 17.28 , \text{ounces} \]
Since the options provided are whole numbers, we can round 17.28 to 18 ounces.
Therefore, the container has about 18 ounces of romaine lettuce.