Variable – an attribute that can be measured

One-variable data sets – give measures of one

attribute for each person/thing

*examples of situations where you see

one-variable data – tally charts, frequency tables, bar graphs, Histograms, Pictographs,

Circle Charts

Two-variable data sets – give measures of

two attributes for each item in a sample.

*Examples of situations where two-

variable data sets are seen are ordered

pairs, scatter plots, two-column tables

of values

State whether each situation involves one-variable or two-variable data. Justify your

answers.

1) Jesse measures the amount of precipitation

each month in Kitchener.

Solution: you can use mean, median and mode to analyse the data so it is a one-variable

situation (also, there is only one attribute

being measured for each month)

2) The study involves statistics about the poverty level in a community and the level of

education.

Solution: The study involves two pieces of data

for each person/family so it is a two-variable

situation (finding relationships between the variables)

a) What type of graph would be best to show

how many hours the students worked during

the week? Justify your answer.

b) What type of graph would be best to

show the relationship between the

number of hours a student spends at

work during the week and weekend.

Justify your answer.

P.133 #1a, 2, 3, 5, 8