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Finding the Fourth Proportional to 522.78, 721.35 and 315.78

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Solution

The fourth proportional to 522.78, 721.35 and 315.78 is: 435.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    522.78 : 721.35 = 315.78 : x
  2. Step 2: Convert to fraction form
    522.78/721.35 = 315.78/x
  3. Step 3: Cross multiply
    522.78x = 721.35 × 315.78
  4. Step 4: Simplify right side
    522.78x = 227,787.90
  5. Step 5: Solve for x
    x = 227,787.90/522.78
  6. Step 6: Final answer
    x = 435.72

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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.