Vertical axis values incorrect

Question

I am creating a simple line chart with 30 days on the x-axis and 10 value points on the y-axis. The data points depicted do not match the values in the spreadsheet, but seem to be random values I have not even used. When I hover over the data point, it shows the correct value. For example, the data point for Day 14 is on 5, but when I hover over that point it correctly states that the value is 2. This is a little embarrassing because I used this as a class demo. What's going on?

Answer 1

I want to clarify the post above. It appears that what is happening is that the line graph is plotting the first column of data, then adding data from the first column to the second column and plotting that as the second column of data, and then adding both the first and second columns together with the third column to plot the third column.  In other words, it is summing to plot points in every column after the first. 

How can I solve this problem? I promised the students I would send the fix when I received it.