Is something measured in a percentage a discrete or a continuous variable?
When you perform one of your experiments, you measure a discrete amount of wash liquid and add it to a discrete amount of water. If you choose to express the quantities in percentages for your convenience, so be it. The percent values are discrete.The correct way to present the data is by bar chart. However, since no unusual sudden changes are expected in the results, it would be ok to connect the bars to form a line function to indicate how the results of untested mixes very probably would have been.
