WASET
	@article{(Open Science Index):https://publications.waset.org/pdf/6014,
	  title     = {New Product-Type Estimators for the Population Mean Using Quartiles of the Auxiliary Variable},
	  author    = {Amer Ibrahim Falah Al-Omari},
	  country	= {},
	  institution	= {},
	  abstract     = {In this paper, we suggest new product-type estimators for the population mean of the variable of interest exploiting the first or the third quartile of the auxiliary variable. We obtain mean square error equations and the bias for the estimators. We study the properties of these estimators using simple random sampling (SRS) and ranked set sampling (RSS) methods. It is found that, SRS and RSS produce approximately unbiased estimators of the population mean. However, the RSS estimators are more efficient than those obtained using SRS based on the same number of measured units for all values of the correlation coefficient.
},
	    journal   = {International Journal of Mathematical and Computational Sciences},
	  volume    = {3},
	  number    = {1},
	  year      = {2009},
	  pages     = {16 - 20},
	  ee        = {https://publications.waset.org/pdf/6014},
	  url   	= {https://publications.waset.org/vol/25},
	  bibsource = {https://publications.waset.org/},
	  issn  	= {eISSN: 1307-6892},
	  publisher = {World Academy of Science, Engineering and Technology},
	  index 	= {Open Science Index 25, 2009},
	}