week 3: central tendency and variability

Question 1

Measures of central tendency

Answer 1

mean
mode
median

Question 2

Measures of variability

Answer 2

range
variance
standard deviation

Question 3

what is Central tendency

Answer 3

most typical or common score

Question 4

Central tendency: The mean

Answer 4

the average score

Question 5

symbols and meaning

Answer 5

S: the sum of
X: a score in the distribution of a variable X
N: the number of scores in a distribution

Question 6

Central tendency: The mode

Answer 6

the most common score in a unimodal (one peak) distribution

Question 7

Central tendency: The median

Answer 7

the middle score when all scores are ranked (usually lowest to highest)

Question 8

when is The median a better measure for central tendency than the mean

Answer 8

in skewed distributions, a few extreme scores can affect the mean

Question 9

skews and central tendency

Answer 9

normal distribution: mode/mean/median equal

skewed distributions both way the median is best to use

Question 10

Variability

Answer 10

how spread out the scores are in a distribution

Question 11

Variability

Answer 11

how spread out the scores are in a distribution

Question 12

Measures of variability

Answer 12

Range
Interquartile range
Variance
The standard deviation

Question 13

Range

Answer 13

difference between the highest and lowest obtained scores

Question 14

Interquartile range (IQR)

Answer 14

boundaries for the middle 50% of scores

Question 15

Variance

Answer 15

how spread out a set of scores is around their mean

Question 16

Sum of Squares (SS)

Answer 16

the sum of the squared deviation scores (numerator of the equation)

Question 17

The standard deviation

Answer 17

SD is the square root of the variance