Ways to display quantitative data

What are the 6 ways quantitative data can be displayed?

Table

Pie Chart

Bar chart: non continuous data

Histogram: continuous data

Line graph

Scattergram (no line through points)

What is the difference between a bar chart and a histogram? (2)

A bar chart compares distinct categories so there are gaps between the bars (eg. eye colour)

A histogram compares continous data so there are no gaps between bars (eg. height)

Histogram (2)

No gaps between bars

X-axis must be continuous data

Scattegram (2)

Used for correlations

Plotted points are not joined together

Table (2)

Includes raw data

Sometimes descriptive statistics

Bar chart (2)

Height represents frequency

Used for nominal data

Line graph (2)

Joins plotted points together

X axis must be continuous data

What is normal distribution? (3)

Symmetrical about the mean - bell shaped curve

Symmetry means the mean, median and mode are all the same

Many human characteristics are normally distributed eg. height and IQ

What is positive skewed distribution? (3)

Cluster of scores at the lower end of data set - curve has a tail to the right

Mode is less than the median, which are both less than the mean

Examples include income and no. of children in a family

What is negative skewed distribution? (3)

Cluster of scores at the higher end of the data set - curve has a tail to the left

Mode is more than the median, which are both more than the mean

An example includes age at retirement