# Investigating gender differences in income

## Overview

In this lesson, students will investigate the relationship between a person’s sex (male or female) and their average employment income. Students will retrieve data from Statistics Canada’s E-STAT database and create scatter plots. Then they will analyse the similarities and differences between two scatter plots (comparing data for provinces/territories and large urban centres) and use informal methods to determine the equations of lines of best fit.

Contributors: David Reed, Queen’s University; Jennifer Hall and Joel Yan, Statistics Canada

## Objectives

• Interpret the meanings of points on scatter plots
• Describe trends and relationships observed in data
• Determine an approximate formula that relates two variables
• Determine the equation of a line of best fit for a scatter plot
• Discuss social justice issues regarding income inequities between the sexes

Mathematics

## Duration

One to two 75 minute periods

## Prior Knowledge

Linear equation in slope-intercept (y = mx + b) form
Slope equation Scatter plots
Line of best fit
Basic knowledge of E-STAT

## Classroom Instructions

1. Review key concepts related to linear relations (e.g., scatter plots, lines of best fit, linear equation in slope-intercept form, slope equation).
2. Using a computer projector, demonstrate the important features of E-STAT (http://www.statcan.gc.cahttp://www.statcan.gc.ca/estat/licence-eng.htm).
3. Hold a brief class discussion about income differences between the sexes. Assess the students’ prior knowledge of this social justice issue and discuss the reasons why these income differences may exist.
4. Distribute the E-STAT instructions and Student worksheet and have students complete the lesson independently or in pairs.

## Enrichment

Have students import the data into a statistical software program or graphing calculator in order to create a scatter plot and determine a line of best fit. Students can then compare the software-generated line of best fit with their estimated line of best fit and discuss any differences.

Have students repeat this process to create a scatter plot for a specific large urban centre near their home. (In Part 2 of the E-STATinstructions, under 5) On the Selection page, students would select a nearby urban centre for Part 1: Select a geographic region). Students can then compare this software-generated scatter plot to the other scatter plots they created previously. If there are any differences, they can research reasons for the differences.

Have students compare the data on employment income from the 2001, 1996, and/or 1991 censuses with the data from the 2006 Census. If there are differences in the scatter plots, the students can research reasons for the differences. (See Teacher resource for graphs of the 2001, 1996, and 1991 Census data.)

Have students read and summarize the findings of the articles listed under ‘Resources’.

Have students create a scatter plot using data on another topic of their choice, selected from any of the census years available in E-STAT. Again, ask students to find the equation of the line of best fit and to describe any trends and relationships in the data.

## Evaluation

Students’ work habits and computer skills can be assessed informally throughout this activity.  They can be assessed more formally through the worksheet, using a marking scheme of the teacher’s choice.