Place plug sets into each solution and continue to measure or weigh them at specified time intervals. The exact time must be determined by the student. Generally 5-10 min. is adequate. If they select a short interval, they will not have enough time to carry out the measurements before the next time interval. Too long a time will provide less data.
Report mean values only for measurements or weights.
At the end of the experiment, determine the percent change in length or weight for the potato in each solution. You have a disc program that will do this automatically and can use your graphing program to draw graphs. Here is an opportunity for the class to use a computer program to do routine math. The actual calculation should be discussed to insure that they understand how and why it is being done. Initial measurement-change at end of experiment.