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Finding the Fourth Proportional to 478.72, 660.54 and 312.61

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Solution

The fourth proportional to 478.72, 660.54 and 312.61 is: 431.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    478.72 : 660.54 = 312.61 : x
  2. Step 2: Convert to fraction form
    478.72/660.54 = 312.61/x
  3. Step 3: Cross multiply
    478.72x = 660.54 × 312.61
  4. Step 4: Simplify right side
    478.72x = 206,491.41
  5. Step 5: Solve for x
    x = 206,491.41/478.72
  6. Step 6: Final answer
    x = 431.34

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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.