Please provide detailed proof. of unbiased estimation

1 . 3.7 Example Suppose Xi ~ POT ( 10 ) ; = 1. .... ~ independently. Determine whether the following estimators are unbiased estimators of O : I1 = ~ Xi * = 2 n - I2 = 6 ~ . ! ~ = ] ~ + 1 ~ ( ~ + 1 ) ` Is unbiased estimation preserved under transformations ? For example , if I is an unbiased estimator of O, is I'_ an unbiased estimator of OZ