Double median ranked set sample (DMRSS) and its properties for estimating the population mean, when the underlying distribution is assumed to be symmetric about its mean, are introduced. Also, the performance of DMRSS with respect to other ranked set samples and double ranked set samples, for estimating the population mean and ratio, is considered. Real data that consist of heights and diameters of 399 trees are used to illustrate the procedure. The analysis and simulation indicate that using DMRSS for estimating the population mean is more efficient than using the other ranked samples and double ranked samples schemes except in case of uniform distribution. Also, using double sampling schemes substantially increase the relative efficiency of ratio estimators relative to their counterpart schemes of one stage samples. Moreover, DMRSS is superior to other double sampling schemes for ratio estimation.
Available at: http://works.bepress.com/hani_samawi/6/