Hello there,

I try to construct a variable with R, but I have some difficulties.

Assume that I use a data set named = mydata. I want to create a variable
that is the mean (totmean) or the sum (totsum) of 6 variables (var1, var2,
var3, var4, var5, var6). However, I want only participants who have
responded to at least 4 items to be include. Those who have one or two
missing for var1-var6 should be coded NA for totmean and totsum.

How I do that?

Thank you!

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