Given a percent goal for majority minority districts, this computes the average
value of minority in non-majority minority districts. This value is "tgt_other"
redist.find.target(tgt_min, group_pop, total_pop, ndists, nmmd)
target group population for majority minority district
A vector of populations for some subgroup of interest.
A vector containing the populations of each geographic unit.
The number of congressional districts.
The number of majority minority districts.
numeric value to target