This paper investigates the random walk behavior of currency returns for 15 African countries, namely, Ethiopia, Gambia, Ghana, Kenya, Madagascar, Mali, Mauritius, Morocco, Nigeria, Rwanda, Sierra Leone, South Africa, Tanzania, Uganda, and Zambia. In particular, the paper applies the...

In a finite population setting, this paper considers a partially rank ordered set (PROS) sampling design. The PROS design selects a simple random sample (SRS) of M units without replacement from a finite population and creates a partially rank ordered judgment subsets by dividing the units in...

When the manufacturing objective is process or product improvement, quality practitioners will frequently resort to one or more approaches within the broader class of response surface methodology. Several techniques, such as the dual response, robust parameter design, and desirability function...