Final answer:
To differentiate bars in a bar chart, one can use colors, patterns, and shades of gray to make the data clear and distinguishable.
Step-by-step explanation:
To differentiate bars in a bar chart, you can use colors, patterns, and shades of gray. These visual tools help to distinguish one bar from another and make the data more understandable and visually appealing. For example, if a bar graph is showing the population data with bars representing different age groups for each year, using different patterns or colors can help to clearly show the distinctions between the data points. Additionally, using shades of gray can be particularly useful when printing in black and white or for viewers with color vision deficiencies.