BUSS1020 Lecture 5: BUSS1020-Lec-5

• School: University of Sydney
• Department: Business Studies
• Course: BUSS1020
• Professor: All

Document Summary

Numerical rvs can be discrete or continuous (no gap b/w values) The set of all possi(cid:271)le out(cid:272)o(cid:373)es is a fi(cid:374)ite, (cid:862)(cid:272)ou(cid:374)ta(cid:271)l(cid:455) i(cid:374)fi(cid:374)ite(cid:863), (cid:374)o. of (cid:448)alues. Only assumes a countable no. of values. E. g. no. of new subscribers to a magazine (must be integer value), no. of absent employees on a given day, prices & price changes (e. g. gap b/w . 2 & . 21) Expected value (measuring centre) e(x: mean (weighted average, e. g. toss 2 coins (let x = no. of heads) E(x) = (0)(0. 25) + (1)(0. 50) + (2)(0. 25) = 1. 0: x = 1 is the mode. In excel, e(x) =sumproduct(1st column, 2nd column) 2nd column is the probability. Variance (measuring dispersion: 1st method e([x e(x)])^2. X e(x) = realisation mean. E(x) is always the same (sum of products of all outcomes & probability) X is one of the possible outcome (e. g. no. of heads: 2, then x = 2) Set 2 columns x-e(x) and [x-e(x)]^2.