Home / 2,120.78-3,181.21-659.89

Finding the Fourth Proportional to 2,120.78, 3,181.21 and 659.89

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Solution

The fourth proportional to 2,120.78, 3,181.21 and 659.89 is: 989.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    2,120.78 : 3,181.21 = 659.89 : x
  2. Step 2: Convert to fraction form
    2,120.78/3,181.21 = 659.89/x
  3. Step 3: Cross multiply
    2,120.78x = 3,181.21 × 659.89
  4. Step 4: Simplify right side
    2,120.78x = 2,099,248.67
  5. Step 5: Solve for x
    x = 2,099,248.67/2,120.78
  6. Step 6: Final answer
    x = 989.85

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.