STAT-3090 Chapter Notes - Chapter 6-8: Cluster Sampling, 3 Women, Sample Size Determination
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Pg 282: a random variable is the outcome of a random process. Random variables can only assume one value at a time, and a chance process always impacts the outcome. In business, everything of interest to a statistics practitioner is a random variable. For example, sales data, inventory levels, product measurements, or profit-loss data. If we made ,001 last quarter, that figure might seem like a deterministic output a(cid:374) a(cid:271)solute (cid:374)u(cid:373)(cid:271)e(cid:396); (cid:271)ut it"s a(cid:272)tuall(cid:455) pa(cid:396)t of a random dataset. Plot 20 or so quarters of historical profit data (when no input was changed), and you will see the random walk a term used by many business people. Or, in the case of having run experiments, do we need to adopt the new st(cid:396)ateg(cid:455)? (cid:863) you"ll (cid:271)e su(cid:396)p(cid:396)ised i(cid:374) fi(cid:448)e (cid:455)ea(cid:396)s of ho(cid:449) ofte(cid:374) the a(cid:374)s(cid:449)e(cid:396) i(cid:374) the (cid:449)o(cid:396)kpla(cid:272)e is (cid:862)(cid:449)ait-and-see. (cid:863) Pg 282: random variables can be discrete or continuous.
