An estimator T_n of θ is said to be more efficient than any other estimator T ^⋅_(n) of θ if and only if

The sample median is _______________ estimate for the mean of normal population.

The mean difference between 9 paired observations is 15.0 and the standard deviation of differences is 5.0. The value of statistic t is

Range of statistic t is

In a contingency table, the expected frequencies are computed under

The term regression was introduced by

The lines of regression intersect at the point

If a constant 50 is subtracted from each of the value of X and Y, the regression coefficient is

If _p is the simple correlation coefficient, the quantity _p² is known as