Find the average and uncertainty of the length of the table?

[Haftred]

I have two measurements for the length of a table (the table is not perfect so it is prudent to measure it on both sides). I get a +/- b and c +/- d as the measurements. Suppose b does not equal d. How can I find the average and uncertainty of the length of the table?

 

[Integral]

Use the larger of the 2 error values.

 

[HallsofIvy]

The "average" is, of course, the average of the two a and c measurements. The uncertainty is, as Integral said, the larger of the two errors.