Chapter 2

Question 1

Central tendency

Answer 1

Typical or most representative value of a group of scores.

Question 2

Mean

Answer 2

Arithmetic average of a group of scores; sum of the scores divided by the number of scores.

Question 3

M

Answer 3

Mean

Question 4

(SPEACIAL) E

Answer 4

Sum of; add up all the scores following this symbol.

Question 5

X

Answer 5

Scores in the distribution of the variable X.

Question 6

Mode

Answer 6

Value with the greatest frequency in a distribution.

Question 7

Median

Answer 7

Middle score when all the scores in a distribution are arranged from lowest to highest.

Question 8

Outlier

Answer 8

score with an extreme value (very high or very low) in relation to the other scores in the distribution.

Question 9

Variance

Answer 9

Measure of how spread out a set scores are; average of the squared deviations from the mean.

Question 10

Deviation score

Answer 10

Score minus the mean.

Question 11

Squared deviation score

Answer 11

Square of the difference between a score and the mean.

Question 12

Sum of squared deviations

Answer 12

total of each score’s squared difference from the mean.

Question 13

Standard deviation

Answer 13

Square root of the average of the squared deviations from the mean; the most common descriptive statistic for variation; approximately the average amount that scores in a distribution vary from the mean.

Question 14

SD^2

Answer 14

variance

Question 15

SD

Answer 15

standard deviation

Question 16

sum of squares (SS)

Answer 16

Sum of squared deviations.

Question 17

Computational Formula

Answer 17

Equation mathematically equivalent to the definitional formula. Easier to use for figuring by hand , it does not directly show the meaning of the procedure.

Question 18

Definitional Formula

Answer 18

Equation for a statistical procedure directly showing the meaning of the procedure.