Goal:
Familiarity with Excel graphing functions.
Instructions:
Example in Google docs (link)
Step 1: Enter the sample data
Step 2: Create a stacked bar chart
Step 3: Make the chart look like a Gantt chart
Example in Microsoft Office Excel (link)
Step 1: Enter the sample data
Step 2: Create a stacked bar chart
Step 3: Make the chart look like a Gantt chart
Other links:
Various videos illustrate this process, see this search on google (terms: gantt, excel, video)