# Math Help - notation question

1. ## notation question

what does the notation

f(theta: Y_1, Y_2.....Y_n) mean?

I believe in this example theta is a parameter of the population sample Y_i.

Does it mean that theta (the parameter itself, say variance or mu) is a function of the population sample? Thanks

2. ## Re: notation question

No. "theta is a function of the population sample" would be " $u= f(Y_1, Y_2, ..., Y_n)$".

This appears to say "we have a function, f, of theta, for given values of $Y_1$, $Y_2$, $Y_2$".
That is, different samples may give different functions of theta, not different theta.