Society of Actuaries (SOA) PA Practice Exam

What common R code function is used to create a histogram for a continuous variable?

1. geom_bar()

2. geom_point()

3. geom_histogram()

4. ggplot2()

The correct answer is: geom_histogram()

The function geom_histogram() is specifically designed for creating histograms in R, particularly within the ggplot2 package. A histogram is a graphical representation that organizes a group of data points into user-specified ranges or bins, making it useful for visualizing the distribution of continuous variables. When using ggplot2, geom_histogram() automatically calculates the counts of observations in each bin and plots these counts against the bins on a bar-like graph, providing an intuitive way to observe the data's distribution. This function allows for additional specifications, such as bin width and aesthetics, to refine the resulting histogram, which enhances its effectiveness in exploratory data analysis. In contrast, the other options provided serve different purposes. For example, geom_bar() is used for creating bar plots with categorical data rather than for continuous variables. geom_point() is utilized for scatterplots, mapping points based on two continuous variables, and ggplot2() refers to the overall package and framework used for creating visualizations in R rather than a specific function. Thus, geom_histogram() is the most appropriate and correct choice for generating histograms.