The ratio of strength of solid to hollow shaft, both having outside diameter D and hollow having inside diameter D/2 in torsion is:
If a sufficient estimator exists it is a function of the _______ estimator.
If Z is a standard normal variate, the proportion of items lying between z=-0.5 and z=-3.0 is
A box contains 12 items out of which 4 are defective. A person selects 6 items from the box. The expected number of defective items out of his selected items is