Skip to content
Q38Section B (Section B)38 of 60

Always-true properties of sample mean and variance

For n≥2n\ge 2, let X1,X2,…,XnX_1,X_2,…,X_n be a random sample from a distribution with E(X1)=0E(X_1)=0, Var(X1)=1\mathrm{Var}(X_1)=1 and E(X14)<∞E(X_1^4)<\infty. Let Xˉn=1n∑i=1nXiandSn2=1n−1∑i=1n(Xi−Xˉn)2.\bar X_n=\frac1n\sum_{i=1}^n X_i\quad\text{and}\quad S_n^2=\frac1{n-1}\sum_{i=1}^n(X_i-\bar X_n)^2. Then which of the following statements is/are always correct?

Multiple select: one or more options are correct. Select all of them, then submit — marks need the exact set.

Options

Select every correct option, then submit.