202notes2__Probability

202notes2_Probabili - Incidental Sample sample of certain available group only given option of one population Biased Sample systematic error self

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
PROBABILITY P = # ways an event can occur # events possible Ex: flipping a coin and getting a tail 1 way to get a tail 1 p = 2 events (head or tail) = 2 = .5 = 50% Additive Rule: "OR" Rule Ex: getting an Ace of Hearts or an Ace of Diamonds 1 1 2 1 52 +52 = 52 = 26 Multiplicative Rule: "And" Rule Ex: getting an Ace and King 4 4 16 52 * 52 = 2704 =.006 *probability of occurrence under normal curve ODDS: NOT probability Partition of events, not probability Frequency of occurrence vs. Non-occurrence Ex: Horse runs 52 races, wins 20, loses 32 For = 20:32 Against = 32:20 WHY KNOW THIS: Want to know if sample is indicative of what is really going on Bigger sample = Better estimate, more samples is better A sample is just a snapshot and although usually close to actual, there is fluctuation between samples and characteristics vary Random Sampling: THE BIG "R" Each element has equal chance in sample Pull many samples How to get Random Sample - "count off" - computer generated list
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Incidental Sample : sample of certain available group, only given option of one population Biased Sample : systematic error, self selection MEAN of the Means • Better than any one mean, more samples • To see how well sample mean estimates true mean, do confidence interval HYPOTHESI Null Hypothesis = Ho • Do not expect any difference • To be nullified Alternative Hypothesis = reject Ho • Assume correct and disprove then favor alternative ALPHA : .001 .01 .05 .10 • The less strict (.05 less strict than .001) the easier to have a "winner" • Importance/involvement determines appropriate strictness Ex: medical procedure - very strict, little margin for error *every industry has different "norm", mean of mean that is acceptable 2-Tail Test : don't know direction of preference/difference (can't predict difference) 1-Tail Test can predict direction of difference (predict winner)...
View Full Document

This note was uploaded on 04/25/2011 for the course MKT 202 taught by Professor Hillman during the Spring '10 term at DePaul.

Page1 / 2

202notes2_Probabili - Incidental Sample sample of certain available group only given option of one population Biased Sample systematic error self

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online