3. My nephew was born last summer. He has 19 cousins on his father's side (it's a big family). I wish to know the mean, #1:, of the distribution of the ages of my nephew's cousins (which is the variable X). I take a sample of 4, with ages X1, X2, X3, and X4. These are all drawn from the same underlying population. Instead of calculating the sample mean of these four, I do the following calculation to create an estimator of ,u, which I call X\". X" = 0.1(X1) + 0.2%) + 030(3) + 0.4m)