summation of two curves with different data points

I am having a hard time to plot the summation of the following curves as the numbers and values of data points of each curve (in blue and black) are different.

Answer 1

[Cris LaPierre]

You are plotting against time. The easiest thing I can think of is putting the underlying data into a timetable and then using the retime function to obtain data points at the same time step in both data sets.

There in an intro to retiming and synchronization with timetables here.

If you are using Live Scripts, there is even an interactive task you could use. Read more about that here.