# psyc312-9

 .remove_background_ad { border: 1px solid #555555; padding: .75em; margin: .75em; background-color: #e7e7e7; } .rmbg_image { max-height: 80px; } To calculate z-score Fromale for z-score to data value X = µ + (zσ) 3 types of probability subjective (personal judgement)Analytic/Theoretical - study all possible outcomesExpected relative frequency (Empirical) - on the long run, average The Addition Rule given mutually exclusive events, sum the probabilitieskeyword: OR Multiplication Rule for joint probabilitieskeyword: AND Chi Square Goodness of Fit Used to test frequency distributions for ONE dimensionEi= npi || df = (k-1) Chi Square: Contingency Er,c = (sum of Row) x (sum of column) sample size df = (r-1)(c-1) When do we reject the null? x2(observed) > x2(critical), reject the null Sampling Error Random variability btwn observations or statistics due to chance Sampling distribution The distribution of a statistic over repeated sampling from a specified population properties of Sample Means the mean of the sample is equal to the population mean (no calculation)the standard deviation of the sample is (standard error of the mean) Variance formula The Null Hypothesis The hypothesis that the manipulation had no effect.always contains = or ≤ or ≥ The alternative hypothesis always contains ≠, < or > The critical values represent the point at which we reject the nullwe reject the null when we exceed the critical value 2 types of hypothesis tests One tailed: one direction for rejection; left or right tailed 2 tailed: rejects null when value is too extreme in either direction; non directional Decision based on a p-value If p ≤ α (in critical region), reject the null If p ≥ α (not in critical region), fail to reject the null Types of errors Type I error occurs if the null hypothesis is rejected but it's actually true (most serious) Type II error occurs when the null hypothesis is not rejected but it's actually false .remove_background_ad { border: 1px solid #555555; padding: .75em; margin: .75em; background-color: #e7e7e7; } .rmbg_image { max-height: 80px; } Authorctryhurn ID25317 Card Setpsyc312-9 Descriptionpsyc Updated2010-06-30T14:22:43Z Show Answers