Final answer:
The number that produces a rational number when multiplied by 0.5 is 2.22.
Step-by-step explanation:
The number that produces a rational number when multiplied by 0.5 is option C, 2.22. A rational number is any number that can be expressed as a fraction, where the numerator and denominator are both integers. When 0.5 is multiplied by 2.22, the product is 1.11, which can be written as the fraction 1/2. Therefore, option C is the correct answer.
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