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Finding the Fourth Proportional to 509.10, 702.78 and 312.64

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Solution

The fourth proportional to 509.10, 702.78 and 312.64 is: 431.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    509.10 : 702.78 = 312.64 : x
  2. Step 2: Convert to fraction form
    509.10/702.78 = 312.64/x
  3. Step 3: Cross multiply
    509.10x = 702.78 × 312.64
  4. Step 4: Simplify right side
    509.10x = 219,717.14
  5. Step 5: Solve for x
    x = 219,717.14/509.10
  6. Step 6: Final answer
    x = 431.58

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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.