In the right-hand side of the dialog box there is a picture of the chosen distribution along with the definition of the parameters of the distributions:

If you choose other distributions, this picture will change.

As is the case for most of the distributions, the lognormal distribution is specified by inserting its 10%, 50% and 90% fractiles. The actual values are inserted in the three fields labelled “a)”, “b)” and “c)”. Since we will be using relative uncertainty for this node, we type in 0.7, 1.0 and 1.5 respectively.

Thus, if we multiply the local factor with the “a)”, “b)” and “c)” values we get 7000, 10000 and 15000 respectively.