By making simple assumptions regarding the nodal potentials we have be
en able to obtain analytic expressions for the mean and standard devia
tion of the cost-function values of a feed-forward multilayer network,
with continuous activation units, prior to training. We have also obt
ained means of the derivatives, with respect to the weights and biases
, of the cost function. The expressions have been used to obtain syste
matic estimates of the learning rate required for back-propagation tra
ining. The results are exemplified using an 8-3-8 encoder network.