Final answer:
The provided information is insufficient to determine the percentage of workers receiving wages between Birr 12.20 and Birr 13.10. Additional data or clarification on wage distribution is necessary to perform an accurate calculation.
Step-by-step explanation:
The information provided does not contain specific data to calculate the precise percentage of workers receiving wages between Birr 12.20 and Birr 13.10. To solve such a problem, we would typically use statistical methods or provided data related to the range of wages. As the numerical values listed in the provided references do not appear to correlate directly with the range of Birr 12.20 to Birr 13.10, we cannot conclude which percentage option, a) 34.13%, b) 47.72%, c) 15.87%, or d) 2.28%, accurately represents the wage bracket in question.
Further clarification or additional data on the wage distribution would be required to answer this question. Generally, we might use a histogram, a frequency distribution, or other statistical methods to determine the percentage of workers within a specific wage range. Without such contextual information or data, it is not possible to determine the correct answer confidently.