Save this script as do_compare_dp_results.sql.

with
  nt_results as (
    select
    bucket, n, min_s, max_s
    from dp_results
    where method = 'ntile')
  ,
  pr_results as (
    select
    bucket, n, min_s, max_s
    from dp_results
    where method = 'percent_rank')
  ,
  cd_results as (
    select
    bucket, n, min_s, max_s
    from dp_results
    where method = 'cume_dist')

select
  bucket,
  (nt.n = pr.n        )::text as "pr n equal",
  (nt.min_s = pr.min_s)::text as "pr min_s equal",
  (nt.max_s = pr.max_s)::text as "pr max_s equal",
  (nt.n = cd.n        )::text as "cd n equal",
  (nt.min_s = cd.min_s)::text as "cd min_s equal",
  (nt.max_s = cd.max_s)::text as "cd max_s equal"
from nt_results nt
inner join pr_results pr using (bucket)
inner join cd_results cd using (bucket)
order by bucket;