In this paper, the bias of the ratioestimator and the estimate of mean square errors of this estimator with known numerator have been compared and discussed.
给出了分子已知情况下比率估计量的偏差和均方误差以及均方误差的估计，并对两类比率估计量进行了比较。
2
According to the characteristic of equipment and stratified sampling theory, the separate ratioestimator is applied to the appraisal of machinery and equipment.
根据设备的特点及分层抽样理论，将分别比估计应用于机器设备整体评估中。
3
We give the approximation formulas of the variance of the sample ratioestimator for a population mean and its asymptotically non-biased estimator in multi-stage sampling.