Final answer:
The range of a graph is the set of possible values that the dependent variable can take. For a function represented by a horizontal line, the range is a single value, corresponding to the constant y-value across the domain. Graphing calculators like the TI-83 series can help visualize the range and identify outliers.
Step-by-step explanation:
The range of a graph represents the difference between the highest and lowest values of the dependent variable (often plotted on the y-axis).
When looking at a graph of a function such as f(x), the range is the set of all possible output values (y-values) that the function can produce within a given domain (the set of x-values).
In the case of a horizontal line graph where f(x) is constant (and hence, does not change as x varies), the range would simply be the single y-value that the horizontal line represents.
For example, if f(x) = 20 for 0 ≤ x ≤ 20, the range is just {20}, since f(x) is 20 regardless of the value of x within the specified domain.
When using tools like the TI-83, 83+, or 84+ graphing calculators, identifying the range visually can also aid in recognizing data behavior and outliers, which are data points significantly different from others in a dataset.
Outliers can sometimes be found by looking at data points that are more than two standard deviations away from a best-fit line on a scatter plot.