I want to write a loop statement to generate a lot of rowmean? How to write such loop statement? Here is each combination of the variables.
Specifically, the rowmean of "psychFlex14 psychFlex15 psychFlex16 psychFlex17", the rowmean of "psychFlex14 psychFlex15 psychFlex17 psychFlex20", ...

Thanks a ton!

Code:
Item
psychFlex14 psychFlex15 psychFlex16 psychFlex17
psychFlex14 psychFlex15 psychFlex17 psychFlex20
psychFlex12 psychFlex14 psychFlex15 psychFlex16 psychFlex17
psychFlex14 psychFlex15 psychFlex16 psychFlex17 psychFlex20
psychFlex12 psychFlex15 psychFlex16 psychFlex17 psychFlex20
psychFlex15 psychFlex16 psychFlex17 psychFlex19 psychFlex20
psychFlex12 psychFlex14 psychFlex15 psychFlex16 psychFlex17 psychFlex20
psychFlex12 psychFlex13 psychFlex14 psychFlex15 psychFlex16 psychFlex17
psychFlex12 psychFlex15 psychFlex16 psychFlex17 psychFlex19 psychFlex20
psychFlex12 psychFlex14 psychFlex15 psychFlex16 psychFlex17 psychFlex18
psychFlex14 psychFlex15 psychFlex16 psychFlex17 psychFlex19 psychFlex20
psychFlex13 psychFlex14 psychFlex15 psychFlex16 psychFlex17 psychFlex20
psychFlex14 psychFlex15 psychFlex16 psychFlex17 psychFlex18 psychFlex20
psychFlex12 psychFlex14 psychFlex15 psychFlex16 psychFlex17 psychFlex19
psychFlex12 psychFlex15 psychFlex16 psychFlex17 psychFlex18 psychFlex20
psychFlex12 psychFlex13 psychFlex14 psychFlex15 psychFlex17 psychFlex20
psychFlex12 psychFlex13 psychFlex15 psychFlex16 psychFlex17 psychFlex20
psychFlex12 psychFlex14 psychFlex15 psychFlex17 psychFlex18 psychFlex20
psychFlex12 psychFlex13 psychFlex14 psychFlex15 psychFlex17 psychFlex18
psychFlex12 psychFlex13 psychFlex14 psychFlex16 psychFlex17 psychFlex20