Implementing User Input for Percentile Calculation in Python

Here's a practical challenge that will reinforce your understanding of user interaction in data analysis. Execute the provided code block to load the `ages` dataset into your Python environment—this will serve as the foundation for our interactive percentile calculator.

Working with this random sample of ages, you'll create a dynamic program that prompts users for input and delivers meaningful statistical insights. Python's built-in `input()` function provides an elegant solution for gathering user information, transforming static data analysis into an interactive experience that engages your audience.

While you'll be testing this functionality yourself in the notebook environment, remember that interactive notebooks serve a broader purpose—they enable stakeholders, analysts, and decision-makers to explore data independently without requiring programming expertise. Your task is to build an intuitive percentile lookup tool where users can enter any percentile value (such as 25, 50, 75, or 90) and receive the corresponding age threshold that defines where that percentage of the population falls.

The output should be clear and professionally formatted. For example, when a user enters 90, your program should return: "90% of all people are less than 61 years old." This phrasing communicates the statistical relationship clearly—you could alternatively use "younger than 61" if that better suits your audience's preferences and communication style.

Similarly, for an input of 40, the program should display: "40% of all people are less than 27 years old." This consistent format ensures users can quickly interpret results across different percentile queries.

Here's a critical implementation detail: the `input()` function always returns string data, regardless of what the user types. Before passing this value to NumPy's `np.percentile()` function, you must convert it to a numeric data type using `int()` or `float()`. This conversion step is essential for mathematical operations and a common source of errors in interactive programs.

Take your time implementing this solution—focus on creating clean, readable code that handles user input gracefully. Once you've completed your implementation, we'll review the solution together and discuss best practices for user input validation and error handling.