This seems a simple question, but I am way too dusty on statistics, so any help will be really appreciated.
Ok, I have one blood sample.
Then, I do a measurement (Aspect Ratio, vertical axis) at different stress levels (horiz. axis). However, I do the measurement under two different viscosity (red and brown in the image). Now, I need to know if the results in Red is significantly different than results in Brown.
Stress and viscosities are independent variables, while aspect ratio is the dependent variable.
Note that every single point in the plot is a single measurement. Thanks.