To emphasize that the number of defects has remained relatively consistent throughout the year, the production manager should use a line graph. A line graph will clearly show the changes in the number of defects over each month and make it easy to see the overall trend and fluctuations throughout the year.
Here is a step-by-step guide to creating the line graph manually:
1. Draw the Axes:
- Draw a horizontal line (the x-axis) to represent the months.
- Draw a vertical line (the y-axis) to represent the number of defects.
2. Label the Axes:
- Label the x-axis from 1 to 12, representing each month (January to December).
- Label the y-axis with appropriate intervals to cover the range of defects (from 18 to 28).
3. Plot the Data Points:
- Using the given data (Month: 1-12, Defects: [18, 21, 22, 25, 28, 25, 24, 18, 20, 21, 26, 28]), plot each point on the graph.
- For example, for Month 1, plot a point at (1, 18); for Month 2, plot a point at (2, 21), and so on.
4. Connect the Data Points:
- Draw lines connecting each consecutive data point to form a continuous line.
5. Add Titles and Labels:
- Title the graph as "Monthly Defect Rate (per 1,000 units)".
- Label the x-axis as "Month".
- Label the y-axis as "Number of Defects".
6. Review for Consistency:
- Look at the graph to ensure it accurately represents the data and the trend is apparent.
- The board of directors should easily observe how the defect rate fluctuates slightly but generally stays within a consistent range, emphasizing stability.
To summarize, a line graph effectively illustrates data trends over time and will emphasize the consistency in the monthly defect rate for the production manager's presentation.
