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Finding the Fourth Proportional to 509.20, 702.69 and 312.82

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Solution

The fourth proportional to 509.20, 702.69 and 312.82 is: 431.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    509.20 : 702.69 = 312.82 : x
  2. Step 2: Convert to fraction form
    509.20/702.69 = 312.82/x
  3. Step 3: Cross multiply
    509.20x = 702.69 × 312.82
  4. Step 4: Simplify right side
    509.20x = 219,815.49
  5. Step 5: Solve for x
    x = 219,815.49/509.20
  6. Step 6: Final answer
    x = 431.69

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.