Final answer:
In this case, Elsa is correct. The number 2.141441444... is actually an irrational number. The likely cause of Richie's error is that he may see a repeating pattern in the number.
Step-by-step explanation:
In this case, Elsa is correct. The number 2.141441444... is actually an irrational number. To be classified as a rational number, a number must be expressed as a quotient of two integers. However, the number 2.141441444... cannot be expressed as a fraction, as it goes on forever without repeating. This is a characteristic of irrational numbers.
The likely cause of Richie's error is that he may see the number 2.141441444... and mistakenly see a repeating pattern. It's important to understand that not all decimal expansions have repeating patterns, and decimals that go on indefinitely without repeating are called irrational numbers.