Mean Help

Thank you but with that formula i don't understand how R can select only the
one with blue eyes

Assuming you're referring to my proposal of

aggregate(height ~ eyes, DATA, mean)

It's not blue eyes only: that will summarize height for each eye color
by taking the mean. Then just select blue eyes and you're good to go.

Finally, I note you're posting from Nabble. Please include context in
your reply -- I don't believe Nabble does this automatically, so
you'll need to manually include it. Most of the regular respondents on
this list don't use Nabble -- it is a _mailing list_ after all -- so
we don't get the forum view you do, only emails of the individual
posts. Combine that with the high volume of posts, and it's quite
difficult to trace a discussion if we all don't make sure to include
context. I'm only following up because I have a hunch this involves my
earlier reply, but it's really not clear.

Cheers,
Michael