Concept:
• The Human Development Index (HDI) is a composite measure of health, education, and income.
• According to UNDP standards, HDI values are classified into categories:
• Very High: Above 0.800
• High: 0.700 to 0.799
• Medium: 0.550 to 0.699
• Low: Below 0.550
Step 1: Identify the threshold for the 'Low' category
Based on the official classification used in geography textbooks (following UNDP guidelines), countries with an HDI value of less than 0.550 fall into the 'Low' development category.
Step 2: Scan the table for values below 0.550
• Belarus (0.801) - Very High
• Botswana (0.708) - High
• Congo (0.593) - Medium
• Mexico (0.781) - High
• Nigeria (0.548) - Low (Below 0.550)
• Sudan (0.516) - Low (Below 0.550)
• Tanjania (0.532) - Low (Below 0.550)
• Chile (0.860) - Very High
• Yemen (0.424) - Low (Below 0.550)
Step 3: Count the matching entries
There are exactly 4 countries (Nigeria, Sudan, Tanzania, and Yemen) whose HDI values are below the 0.550 mark.