Take "Airline Delays.JMP" as an example,using JSL:
1. Figure out the number of Feb months with the value <-30 in column "Arrival Delay", and the average value of these data 2. Figure out the number of months that are not Feb months, and the value of column "Arrival Delay" <-30, and the average value of these data
The 4 values of the result can be displayed in the "Airline Delays.JMP" file or saved in a new file.Thanks!
The simplest way would be to add two new columns that answer your two questions with either a 0 or 1. Next select both columns, right click on the heading and pick - New Formula Column - Group By. Third right click on the Arrival delay - New Formula Column - Mean. The new column it creates will contain the 4 numbers you are interested in (The average arrival time grouped by if it is Feb and if the delay is more than 30 minutes or not).