Signature length 1

Set the question:
How long is a typical year X student’s signature?

Data collection

Negotiate rules for collecting data:

• write either/or both first and last name
• use a pencil or ballpoint pen,
• dominant or non-dominant hand.

Measure in mm (discuss the need for accuracy).

Discuss how many measurements would be needed to make a reliable prediction.

Representing data

List and order data for the class.

Create a stacked dot plot for class data.

Summarising data

Discuss information shown in the class data plot.

For the stacked dot plot discuss the mean, median, mode, range, clumps, humps, gaps and outliers.

Create a box-and-whisker plot (if appropriate for year level). How does it help describe the data set?

Degree of certainty

What aspects of the investigation affect the variation in the data and the uncertainty of the conclusion?

Would the data look the same if another class collected the data (perhaps in another country)?

Drawing an informal inference

Write a report, including all of the assumptions made and limitations experienced, to explain how the class arrived at the length of the typical year X student’s signature.