Scale axis in Excel chart

Question

I have made a record of some samples at different seconds:

50  40  36  33  32  30  28  25  22  20  17  15  13  10  7   5

When I create a line chart with markers in Excel, the x-axis is based on these values, but of course they are not normalised in the sense that there is the same distance from 50 to 40 than from 22 to 20.

Is there a way I can draw the line with the markers only at the positions I have recorded and that is properly scaled in the x-axis? (so from 50 to 40 there is no data in the middle but the line does not go down to "0", it should just link to the value at 40 smoothly. Format Axis does not seem to do anything here)

EDIT - see graph

Answer 1

Example of Scatter with Smooth Lines and Markers:

As the @Jon Peltier has kindly mentioned, prior to this edit I had incorrectly described the above as Scatter with Straight Lines and Markers.

Jon has also pointed out how this happens to be an example of the potential for smooth lines to be deceptive. If the vertical scale were percentages then anything over 100 might not be possible, though the 'bump' in the chart would indicate otherwise!

An alternative with Straight lines is shown below, where 'B' values as displayed have been changed to represent the sum of A and B values, as possibly nearer the OP's requirement: