Most seasons 76 points would be enough for the play offs. It will probably be more this year as the top 7 are far ahead of the rest of the division. Southampton can get a maximum of 86 points. Can they drop less than 10 points for the rest of the season? Seems unlikely. A record of won 9 drawn 5 over the last 14 games would probably still see them miss out.
On a side issue this year I suspect that the total to stay up will be less then 50 points too as it is so close at the bottom.
Have a look at there run in.