Hi, I don´t know how this standard type uncertainty calculation can be solved. The situation is as follows: on a graph are three curves with different values, their slope is the speed of each car. The uncertainty of the y-axis (time) is 5%. Now the problem is that i want to display the values of the speeds in a table and as such a "universal" uncertainty should be given on top. I calculated the uncertainty of the fastest of the three cars to be +-0.3 m/s, the slowest car speed (ie slope) has a uncertainty of 0.5m/s. What value should I give for the universal uncertainty? Is it the average of the fastest and slowest? I feel somehow that it cannot be, as the average would be 40%, which would not agree with either of the values.. I did not find a similar problem in the internet (only one curve..), if you got any page of help, please redirect. Thank you!