Classifying and Representing Data

Question 1

Categorical - nominal

Answer 1

Name does not suggest order

Question 2

Categorical - ordinal

Answer 2

Name suggests order

Question 3

Numerical - discrete

Answer 3

Data can only take exact numerical values such as 0 or 1

Question 4

Numerical - continuous

Answer 4

Data that can take any numerical value such as 71.25

Question 5

Random sample

Answer 5

Members of the population have an equal chance of being selected.

Question 6

Stratified sample

Answer 6

Categories of a population are chosen such as male/female. The
members are randomly selected from each category.

Question 7

Systematic sample

Answer 7

Population is divided into a structured sample size. The members are orderly selected from this structure, such as each 3rd person in order.

Question 8

Self-selected sample

Answer 8

Members of the population volunteer themselves.

Question 9

Dot plot

Answer 9

A number line with each data point marked by a dot.

Question 10

Stem-and-leaf plot

Answer 10

Used to present a small (less than 50 values) numerical data set. The ‘tens’ digit of the data values becomes the ‘stem’ and is written in numerical order down the page. The ‘units’ digits become the ‘leaves’ and are written in numerical order across the page.

Question 11

Grouped frequency table

Answer 11

1. Classes are listed in ascending order.
2. Tally column records the number of times the score occurred.
3. Frequency column is a count of each outcome or class.

Question 12

Cumulative frequency

Answer 12

The frequency of the score plus the frequency of all the scores less than that score.

Question 13

Frequency and cumulative frequency graphs

Answer 13

1. Frequency histogram is a column graph that uses the score as the horizontal axis and frequency as the vertical axis.
2. Cumulative frequency histogram is a column graph with the score as the horizontal axis and cumulative frequency as the vertical axis.
3. Frequency polygon is a line graph of a frequency table. It can be constructed by joining the mid-points of the bars of the histogram.
4. Cumulative frequency polygon or ogive is a line graph constructed by joining the top right-hand corner of the rectangles in a cumulative frequency histogram

Question 14

Pareto charts

Answer 14

A Pareto chart combines a frequency histogram and cumulative frequency line graph.