ECO220Y1 Lecture 1: Lecture 1

• School: UTSG
• Department: Economics
• Course: ECO220Y1
• Professor: Jennifer Murdock

Document Summary

A mean number of income in ut alumni. We will not get down to the exact parameter (too hard) Mean income of the 50th randomly selected alumni. Inferential statistics: make inference about a population and its parameters using data. - population mean (parameter) sigma population standard deviation (parameter) Sampling error: the purely random difference between a sample and the population that arises because the sample is a random subset of the population. Also (cid:272)alled: (cid:862)(cid:449)hite (cid:374)oise(cid:863) or (cid:862)sa(cid:373)pli(cid:374)g (cid:374)oise(cid:863) As sample size gets larger the sampling error tends to get smaller. Related to (cid:862)sa(cid:373)pli(cid:374)g (cid:448)aria(cid:271)ility(cid:863) differences between one sample and another. There"s sa(cid:373)pli(cid:374)g error (cid:271)et(cid:449)ee(cid:374) true proportio(cid:374) of populatio(cid:374) a(cid:374)d sa(cid:373)ple (cid:862)co(cid:373)(cid:373)o(cid:374) se(cid:374)se does (cid:374)ot (cid:449)ork i(cid:374) statisti(cid:272)s(cid:863) The amount of sampling error depends on the sample size, not the sample size relatively to the size of population. Pctdbt95: government debt as a percentage of gdp in 1995. 2 types of info; 2 types of variables.