Displays of quantitative data

Question 1

Features of graphs and tables

Answer 1

Should clearly show the findings from a study.
There should be a short but informative title.
In a graph:
Both axes should be clearly labelled.
In the case of a bar chart or histogram the x-axis is usually the independent variable and the y-axis is usually the frequency.

Question 2

Frequency table

Answer 2

Data that tells you how frequently certain items occurred.

Question 3

Bar chart

Answer 3

A graph used to represent the frequency of data.
The categories on the x-axis have no fixed order and there’s no true zero.
There’s a space left between each bar to indicate the lack of continuity.

Question 4

Histogram

Answer 4

Type of frequency distribution in which the number of scores in each category of continuous data are represented by vertical columns.
There’s a true zero.
There’s no spaces between the bars.

Question 5

Pie chart

Answer 5

A circular graph divided into sections or “slices” each representing the proportion of the total.
The size of each slice is calculated by working out the appropriate proportion out of 360.

Question 6

Scatter diagram

Answer 6

Used when doing a correlational analysis.

Question 7

Line graph

Answer 7

Has continuous data on the x-axis.
There’s a dot to mark the top of each bar.
Each dot is connected by a line.

Question 8

Normal distribution

Answer 8

A symmetrical bell-shaped frequency distribution.
This distribution occurs when certain variables are measured.
Such “events” are distributed in such way that most of the scores are clustered close to the mid-point.
The mean, median and mode are at the mid-point.

Question 9

Skewed distribution

Answer 9

A distribution is skewed if one tail is longer than another, signifying that there are a number of extreme values to one side or the other of the mid-score.

Question 10

Positive skewed distribution

Answer 10

Most of the scores are bunched towards the left.
The mode is to the left of the mean because the mean is affected by the extreme scores tailing off to the right.

Question 11

Negative skewed distribution

Answer 11

Most of the scores are bunched towards the right.
The mode is to the right of the mean because the mean is affected by the extreme scores tailing off to the left.