A simple random sample {Y1, Y2, ..., Yn} is taken from a population of mean u and variance a2, such that E[y] =u and v[y]= a {1,2....n]. (a) The sample

mean is defined as \bar{Y}=\frac{1}{n} \sum_{i=1}^{n} Y_{i} (b) The sample variance is defined as Show that E[s²] = o². You may use the fact that V[Y] = a²/n without proving it.