Final answer:
The HBOX statement is used to create a horizontal boxplot in the PROC SGPLOT step. In contrast, histograms visualize data distribution and are analyzed by drawing a smooth curve through the tops of the bars to describe the shape of the data's distribution.
Step-by-step explanation:
To create a horizontal boxplot using the PROC SGPLOT step in SAS, you should use the HBOX statement. The HBOX statement specifically generates a horizontal box plot of the data. Box plots provide a visual summary of key quartiles of a dataset, highlighting the median, the spread, and potential outliers. These are distinct from bar graphs or histograms, which display frequency or count data using bars. While bar graphs consist of bars that can be vertical or horizontal, a histogram shows the distribution of a continuous variable and is typically made of vertical bars with no gaps between them to represent different intervals (or 'bins') in the data.
When analyzing a histogram, you may draw a smooth curve through the tops of the bars to infer the general shape of the distribution. This smooth curve helps identify key characteristics such as whether the distribution has a symmetric bell shape, a skewness to the right or left, or other significant features like uniformity or bimodality. The shape depicted by the smooth curve provides insight into the underlying data distribution.