Chapter 2- Exploring Data: Frequency Distributions and Graphs

Question 1

Simple frequency distribution

Answer 1

Scores arranged from highest to lowest, with the frequency shown for each score

Tells you where the majority of the data lie. Don’t care about individual people, care about most

Pick up valuable info with just a glance, can easily see measures of central tendency

Question 2

Raw scores/data

Answer 2

Score obtained by observation/experiment

Question 3

How to make a simple frequency graph

Answer 3

1. Make labels/titles- variable, tally, frequency, cumulative frequency, graph title
2. Write all numbers from highest to lowest
3. Put tally scores in that column (tallies only used for rough drafts)
4. Put amount of tallies in frequency box
5. By the end of cum. Frequency it says N

Question 4

Grouped frequency distributions

Answer 4

When your data is all over the place, use grouped to simplify it down

These are scores compiled into equal sized Intervals, includes the frequency of score in each interval

Should be 10-20 groups

Question 5

Frequency distributions are what kind of statistics?

Answer 5

Descriptive statistics. Because it describes a particular characteristic of data
Show us where the majority of the data lie, a characteristic

Question 6

Quantitative graphics?

Answer 6

Frequency polygon or histogram

Question 7

Frequency polygon

Answer 7

A frequency distribution graph used to graph quantitative variables

The frequency points are connected by lines

Each point represents two numbers: the class midpoint directly below it on the X axis and the frequency of the class directly across from it on the Y axis

Name of the variable being graphed goes on the x axis

Question 8

How to make a frequency polygon

Answer 8

Variable name on x axis
X- variable
Y-Frequency

Dots are midpoint of the intervals

Question 9

Histogram

Answer 9

Quantitative graphing technique

Made by raising X bars to the appropriate frequencies

Question 10

When to use frequency polygon v histogram?

Answer 10

If you are displaying two overlapping distributions on the same axes, a frequency polygon is less cluttered than a histogram

But on a histogram- it is easier to read frequencies, and are a better choice when presenting discrete data

Question 11

Qualitrative data?

Answer 11

Bar graph

Question 12

Bar graph

Answer 12

Represents qualitative variable

Looks like a histogram but has wider space between bars

Use with an ordinal or nominal scale

Question 13

Symmetrical distributions

Answer 13

Have two halves that more or less mirror each other

Question 14

2 types of symmetrical distribution

Answer 14

Normal distribution

Rectangular distribution

Question 15

Normal distribution

Answer 15

Bell shaped distribution

Question 16

Rectangular distribution

Answer 16

Literally looks like a rectangle, occurs when the frequency of each value on the x axis is the same

Question 17

Skewed distributions

Answer 17

Scores that most frequently are near one end of the scale, leaving few scores on the other

Question 18

Positively skewed

Answer 18

Thin point to the right

Mode, median, average

Question 19

Negatively skewed

Answer 19

Thin point to the left

Average, median, mode