Workshop 4 - Graphs

Question 1

Absolute frequency

Answer 1

The number of times you have observed that value (count)

Question 2

Relative frequency

Answer 2

the number of times you have observed a value, expressed as a percentage.

Question 3

Valid frequency

Answer 3

If someone leaves a question blank, you can calculate the relative frequency compared to everyone who answered that question.

Question 4

Cumulative frequency

Answer 4

To find the cumulative relative frequency you add the relative frequencies of a group to the percentages of the previous groups.

Question 5

Bar graph

Answer 5

Best be used if there are not too man groups + the groups all have sufficiently high frequencies. Variables on the nominal or ordinal level. The bars have to be separate.

Question 6

Clustered bar graph

Answer 6

Two bar graphs combined into one. Nominal or ordinal level.

Question 7

Histogram

Answer 7

• Divide your data into fixed groups
• You determine how many groups you want
• The bards are stacked against each other to show that the groups are connected
  Interval / ratio level

Question 8

Pie chart

Answer 8

Nominal or ordinal

Can see the ratios between groups less well than bar chart.

Question 9

Line graph

Answer 9

• You put time on the horizontal axis (X-axis)
• You put the variable of interest on the vertical axis (Y-axis)
• Shows the progress of a variable over time.
  Interval / ratio level

Question 10

Box plot

Answer 10

Looks at the centre of your data and variation
Three parts:
- middle bar (mean)
- box (Q1 -> Q3)
- lines (min and max)