Unit 2

Question 1

Frequency

Answer 1

counting the number of times a score occurs
Symbol = 𝑓

Question 2

Distribution

Answer 2

any organized set of data (i.e., scores)

Question 3

4 ways to organize data:

Answer 3

1. Simple frequency
   2.Relative frequency
2. Cumulative frequency 4.Percentile

Question 4

A Bar Graph is

Answer 4

Used for nominal or ordinal data
Bars DO NOT touch

Question 5

A Histogram is

Answer 5

Used for a small number of scores, interval, or ratio data
Bars DO touch

Question 6

A polygon is

Answer 6

Use with a large number of interval or ratio scores
Continuous variable

Question 7

Relative Frequency

Answer 7

the frequency of all scores at or below a particular score

Question 8

Percentile

Answer 8

the percent of all scores in the data at or below a particular score

Question 9

Grouped Frequency Distribution:

Answer 9

Method to describe large data sets

Question 10

How many intervals in a grouped FD table?

Answer 10

10-12

Question 11

What is the interval width in a grouped FD table?

Answer 11

Simple value…. 2, 5, 10, or 20

Question 12

Central Tendency

Answer 12

Calculating one number that summarizes everyone’s score

Question 13

Measures of Central Tendency:

Answer 13

Mean, Median, Mode

Question 14

The Normal Distribution

Answer 14

Represents the ideal distribution of scores in a population
- The basis of inferential statistics

Question 15

Range

Answer 15

The most frequently occuring score

Question 16

Kurtosis

Answer 16

Still symmetrical, refers to the distribution of scores relative to the middle

Question 17

Skewed Distribution

Answer 17

• Only one pronounced tail
• Measure of the degree of asymmetry

Question 18

When is the mode used?

Answer 18

Nominal/ordinal scales of measurement

Question 19

Mode limitations:

Answer 19

• more than 2 modes, difficult to describe the data
• Skewed distributions

Question 20

The Median

Answer 20

The score at the 50th percentile (50% of all scores at or below the median)
Uses: nominal and ordinal scores, and skewed distributions

Question 21

The Mean - most commonly used

Answer 21

Refers to the score located at the mathematical centre of the distribution

Question 22

Mean (average) symbols

Answer 22

X̅ (sample)
μ = population

Question 23

Measures of Variability

Answer 23

Describes the extent to which scores in a distribution differs from each other

Question 24

The Range

Answer 24

The distance between the 2 most extreme scores in a distribution

Question 25

Score Deviation (standard deviation)

Answer 25

Refers to the “distance” between an individual score and a sample mean

Question 26

The magnitude of score’s deviation is referred to as an

Answer 26

Error

Question 27

Deviation formula

Answer 27

Score subtract the average: x - X

Question 28

Calculating SD steps:

Answer 28

1. Calculate average (mean)
2. Compute deviations = x - x̄
3. Square the deviation values
4. Calculate sum of squares (SS)
5. Divide SS by (N-1) variance
6. Square root the variance - standard deviation

Question 29

Normal Distribution and Z-Score

Answer 29

Any known score (x) can be expressed as a z-score by knowing the mean and SD of the distribution