I would like to remove all rows with 3 or more NA values - below is an example of my data set (but the actual data set has 95,000 rows)
Plot_ID Tree_ID Dbh13 Dbh08 Dbh03 Dbh93_94
106 6 236 132 123 132
204 5 NA NA NA 142
495 8 134 NA NA 102
984 12 NA 123 110 97
So that it looks like this
Plot_ID Tree_ID Dbh13 Dbh08 Dbh03 Dbh93_94
106 6 236 132 123 132
495 8 134 NA NA 102
984 12 NA 123 110 97