Univariate Data

NZ Level 5

Recognising the spread of data

Lesson

We've already learnt about the range, which is a measure of spread in a data set. Once we are able to calculate the range in a data set, we can start to compare and make judgments about different data sets and potentially spot any outliers.

Now let's compare the spread of some data sets and graphs.

Look at the data sets below. Which data set has the largest range?

$101,105,118,129,136$101,105,118,129,136

A$19,23,25,28,29$19,23,25,28,29

B$22,25,43,64$22,25,43,64

C$104,107,113,120,125$104,107,113,120,125

D$101,105,118,129,136$101,105,118,129,136

A$19,23,25,28,29$19,23,25,28,29

B$22,25,43,64$22,25,43,64

C$104,107,113,120,125$104,107,113,120,125

D

Do the dot plots shown have the same range?

Yes

ANo

BYes

ANo

B

Plan and conduct surveys and experiments using the statistical enquiry cycle:– determining appropriate variables and measures;– considering sources of variation;– gathering and cleaning data;– using multiple displays, and re-categorising data to find patterns, variations, relationships, and trends in multivariate data sets;– comparing sample distributions visually, using measures of centre, spread, and proportion;– presenting a report of findings