When deciding how to effectively present data in a graph, the type of graph chosen should clearly convey the relationships and comparisons you want to emphasize. In Rachel's case, she wants to emphasize the relation of each city's precipitation to the others at each point in time (each month of the year).
Here's a step-by-step solution to why a particular graph type would be appropriate:
1. Comparison Across Multiple Groups: Rachel wants to compare the precipitation in three different cities. A graph that can display this comparison across multiple groups (Boston, Phoenix, and Minneapolis) at each monthly interval is important.
2. Time Series Data: The data is collected over a sequential time period (months of the year). Ideally, the graph should clearly show changes over time for each city.
3. Emphasizing Relationships: A graph that can highlight the differences and similarities in precipitation levels between the three cities at each month would be helpful.
Given these criteria, the most appropriate type of graph would be:
- Line Graph: This graph is particularly effective for displaying data trends over time. Each city can be represented by a separate line, and their respective precipitation amounts plotted over the months. This allows for easy visual comparison of how precipitation levels change with time in each city and how the cities relate to each other in terms of precipitation.
Therefore, the appropriate answer is:
b. line graph
