In Tables 5 and 6, we summarize the results for when the population mean of X is unknown. The double-sampling method
is used to estimate μX . Since the two estimators μˆ ′ YMRSSk and μˆ ′ YSRSk are biased, the efficiency of μˆ ′ YMRSSk with respect to μˆ ′ YSRSk is obtained using