PSYC1011 Study Guide - Final Guide: Confidence Interval, Sampling Distribution, Standard Deviation
Document Summary
Sample mean = (combination of rv) Tied to the distribution of the average. When we take an srs + measure the sample average of a variable. Then for sufficiently large n it is approx. true that: ^ the distribution of the average is approx. normal. Whe(cid:374) (cid:449)e (cid:373)easure x (cid:449)ith (cid:373)ea(cid:374) a(cid:374)d sta(cid:374)dard de(cid:448)iatio(cid:374) Clt tells us the form of the approx. sampling distribution of . Does(cid:374)"t (cid:373)atter a(cid:271)out distri(cid:271)utio(cid:374) of i(cid:374)di(cid:448). out(cid:272)o(cid:373)es. If we know the sampling distribution of a stat = we can understand its behaviour. Co(cid:374)fide(cid:374)(cid:272)e i(cid:374)ter(cid:448)al for (cid:449)he(cid:374) (cid:449)e do(cid:374)"t k(cid:374)o(cid:449) a(cid:374)(cid:455)thi(cid:374)g. % of area under bell curve = confidence level. Allows us to make general statements (inferences) a(cid:271)out (cid:271)ased o(cid:374) just a sa(cid:373)ple. Exploits how normal behaves = gives a buffer = gives a region rather than a point. We can use what we know about normal distributions to find a range of values that we. Use to esti(cid:373)ate if r is take(cid:374) the(cid:374)
