Quiz 9.3

A population has sum of squared deviations, SS = 100 and variance, s 2 = 4. What is the value of mean deviation score [Σ(x-mean)] for the population?​

The mean deviation score always equals to zero. That is why we need to square the deviation scores when we calculation the standard deviation

What is the value of SS (sum of squared deviations) for the following population? Population: 1, 1, 1, 5​

The mean of distribution is (1+1+1+5)/4=2 1-2 = -1 1-2 = -1 1-2 = -1 5-2 = 3 List of squared deviations: 1, 1, 1, 9. The sum of square deviation is 1+1+1+9= 12

What is the value of SS (sum of squared deviations) for the following population? Population: 2, 3, 0, 5

The mean of distribution is (2+3+0+5)/4=2.5 2-2.5 = -0.5 3-2.5 = 0.5 0-2.5 = -2.5 5-2.5 = 2.5 List of squared deviations: 0.25, 0.25, 6.25, 6.25. The sum of square deviation is 13

What is the value of SS (sum of squared deviations) for the following set of scores? Scores: 8, 3, 1​

The mean of distribution is (8+3+1)/3=4 8-4=4 3-4=-1 1-4=-3 List of squared deviations: 16, 1, 9. The sum of square deviation is 26

A sample consists of n = 16 scores. How many of the scores are used to calculate the range?​

The range, by definition is the difference between the highest and lowest scores.

In a population of N = 10 scores, the smallest score is X = 8 and the largest score is X = 20. Using the concept of real limits, what is the range for this population?​

The upper real limit of 20 is 20.5 and the lower real limit of 8 is 7.5. Therefore, the range is 20.5-7.5 = 13.

A population of N = 6 scores has Σ X = 12 and Σ X2 = 54. What is the value of SS for this population?​

Using the computational formula: SS = ∑X2 - (∑X)2/N = 54 - 122 / 6 = 54 - 24 = 30

A population has sum of squared deviations, SS = 100 and variance, s 2 = 4. How many scores are in the population, given that the formula for variance is s2 = SS/N

You would need to use algebra to transform the equation, but the calculation should be straightforward