Need Help Graphing Multiple Graphs into One Graph

#1
Hello,

I am an undergraduate student in biology. I have not yet completed a statistics course but I do have basic familiarity with graphing in excel.

Here is the problem:

We did an experiment in lab and we are supposed to write up a lab report which includes graph. We are given the class data after the experiment. There are 6 different graphs showing the same trend but I have no clue how to graph them on a single graph, showing confidence intervals and such.

I have attached 2 of the 6 graphs to show you what I am working with.

For some background information, a muscle was stimulated with increasing intensities. These graphs are supposed to represent whether or not a muscle contraction is graded or an all-or-none response.

I can measure the amplitude of the blue lines. I thought of shifting the x-axis of the graphs and averaging the values it takes to reach maximum. A problem arises because the gastrocnemius muscles used from different frogs took a different amount of time to reach a maximum- some very quick, some slowly.

Any idea what I can do? Any data manipulation techniques? Any techniques to reduce variability?

Thank you.