e/m ratio

1.

2. Plotting Error Bars (My Example):

a. Select x's and y's

b. Right click the data points, and choose "Format Data Series"

c. In "Error Bars", for both x and y error bars, choose "Both" in "Display", and "No cap" in "End style".

d. In "Marker Style", choose "No Marker"

Then the error of the data can be easily seen. The default marker is too large and may block the errors.