PPT 4 - Variability

Question 1

Variability

Answer 1

degree to which the ind. data points are distributed around the mean

Question 2

3 measure of variability

Answer 2

-range
-variance
-standard deviation

Question 3

Range equation

Answer 3

highest - lowest

Question 4

Variance

Answer 4

average of the squared deviation’s from the mean

Question 5

Population variance

Answer 5

sum of the squared deviations from the mean divided by population size

Question 6

Sample variance

Answer 6

sum of the squared deviations (SS) from the mean divided by (sample size n-1)

Question 7

Bias happening

Answer 7

underestimating population variance

Question 8

Standard deviation

Answer 8

measure of the average deviation of each score from the mean

Question 9

Standard deviation (percentages)

Answer 9

68% within 1 SD
95% within 2 SD
99.7% within 3 SD

Question 10

Outliers effect

Answer 10

Range - increase
Variance - increase
SD - increase

Question 11

S factors

Answer 11

add/subtract - no effect
multiply/divide - constant
multiply/divide s^2 - constant squared