PSYCH 100A Lecture 4: Lecture 4
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Ex) using the center of town to create data in numbers: average distances, find the mean. Deviations always sum to zero: when computed relative to the mean, to compute the average deviation (distance) Ignore the negatives and add them all up, divide by the number of scores. To compute: deviation score is another name for error, (x-mu, score for one participant - population mean, distance between a score and the mean (center of distribution, square deviation scores, (x-mu)^2, deviation scores must sum to zero. The variance is the average squared deviation: to unsquare - you just square root. Ex) typical respondent is +/- 6. 87 points from the mean: average of the distances from the mean. A problem with the population formula: computes error relative to the true population mean, we will never know the true population mean, sample mean is not the same as the actual population mean.