Explain the following desirable properties of an estimator: Unbiasedness, efficiency, consistency and sufficiency (using maximum of 200 words)

Explain the following desirable properties of an estimator: Unbiasedness, efficiency, consistency and sufficiency (using maximum of 200 words). 3. There is a two-way causation in correlation analysis where as there is a one-way causation in regression analysis. Explain briefly using maximum of 200 words 4. A sample of 20 observations corresponding to the regression model Yi ? ? ? ?Xi ?Ui gave the following data. ? ? ? ? ? ?? ? 106.4 186.2 215.4 21.9 86.9 2 2 ? ? ? ? ? ? ? ? ? ? ? ? ? ? X X Y Y X X X Y Y Y i i i i i i A. Estimate ? and ? and interpret the resul