The residents of Lake Bradford are angry about the canal between Lake Bradford and Lake Jackson. This canal has allowed too many tiger minnows into Lake Bradford, and, as a result, the value of the lake property on Lake Bradford has gone down considerable. One solution would be to place a one-way dam in the canal. This would only reduce the fraction of the tiger minnows migrating from Lake Jackson to Lake Bradford. In other words, the dam would have the effect of reducing the probability of a tiger minnow migration from Lake Jackson to Lake Bradford. What would this probability have to be to restore the original number of tiger minnows in each lake?