sol4 - Chapter 4 Variability 1 a SS is the sum of squared...

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Chapter 4: Variability1. a. SSis the sum of squared deviation scores.b. Variance is the mean squared deviation.c.Standard deviation is the square root of the variance. It provides a measure of the standard distance from the mean.2. SScannot be less than zero because it is computed by adding squared deviations. Squared deviations are always greater than or equal to zero.3. Standard deviation and variance are measures of distance and are always greater than or equal to zero.4. A standard deviation of zero indicates there is no variability. In this case, all of the scores in the sample have exactly the same value.5. Without some correction, the sample variance underestimates the variance for the population. Changing the formula for sample variance (using n– 1 instead of N) is the necessary correction. 6. a. No. X= 70 is 10 points away from the mean, only ½ of the standard deviation.b. Yes. With s= 5, 10 points is equal to a distance of 2 standard deviations.7. a. s= 2 is better (you are above the mean by 3 standard deviations).

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