Shree GaneshA Statistics

🔖Statistical Inference I ( Theory of estimation : Efficiency)  In this article we see the  terms:  I. Efficiency. II. Mean Square Error. III. Consistency. 📚 Efficiency:  We know that  two unbiased estimator of parameter gives rise to infinitely many unbiased estimators of parameter. there if one of parameter have two estimators then the problem is to choose one of the best estimator among the class of unbiased estimators. in that case we need to some other criteria to to find out best estimator. therefore, that situation  we check the variability of that estimator, the measure of variability of estimator T around it mean is Var(T). hence If T is an Unbiased estimator of parameter then it's variance gives good precision. the variance is smaller then it give's greater precision. 📑 i. Efficient estimator: An estimator T is said to be an Efficient Estimator of 𝚹, if T is unbiased estimator of    𝛉. and it's variance is less than any other estimator. i.e. Var(T) < Var(T