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Finding the Fourth Proportional to 840.18, 1,261.06 and 429.61

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Solution

The fourth proportional to 840.18, 1,261.06 and 429.61 is: 644.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.18 : 1,261.06 = 429.61 : x
  2. Step 2: Convert to fraction form
    840.18/1,261.06 = 429.61/x
  3. Step 3: Cross multiply
    840.18x = 1,261.06 × 429.61
  4. Step 4: Simplify right side
    840.18x = 541,763.99
  5. Step 5: Solve for x
    x = 541,763.99/840.18
  6. Step 6: Final answer
    x = 644.82

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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.