Psyc 3510 1st EditionExam # 4 Study GuideLecture #5 Outline A. Mean, median, mode, sum of squares, sample variance, standard deviation 1. An example of one of these problems was in Lecture #5. 2. The best formulas to use for the last three equations are as follows: a. SS= ∑X2−(∑x)2/ N b. SD2=SSn−1 c. SD= √SS /n-1 Lecture #6 OutlineA. Histograms, Frequency Polygons, Interquartile Range1. Examples and descriptions are in the outline. Lecture #7 OutlineA. Inferential StatisticsB. Chi Square and Hypothesis testing1. Goodness-of-Fit, Independence2. 3 properties of chi squarea. Variablesb. A description of what happenedc. Statistical copy- what the numbers actually areC. Example: Goodness-of-Fit1. Null Hypothesis: H0;No effect Experimental Hypothesis: H1;Preference2. A>.05 Fail to reject the null hypothesis3. A<.05 Reject the null hypothesisPreference of apples, oranges, or pears; only one variable is being observedApple: 5 Oranges: 3 Pears: 7N=15x2=∑(Fo−Fe)2/ Fe(5−5)25=(0)25=0(3−5)25=(−2)25=.8(7−5)25=(2)25=.8After adding each total together, the answer is 1.6. Now use the degree of freedom (n-1) to find whether to reject or accept the null hypothesis. In this case, df= 2. Thenlook at the critical value table to find the significance level. 4. To find the expected when given the observed, take the decimal and multiply it by the total population. 5. You want to reject the null hypothesis in order to decrease the possibility of a Type I Error. The degree of freedom needs to be greater than .05.D. In a test of independence1. Based on columns (c) and rows (r), the total of each will get your population (n).2. Fe= (R total) (C total)/ N3. Df= (c-1)
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