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Finding the Fourth Proportional to 619.92, 855.50 and 387

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Solution

The fourth proportional to 619.92, 855.50 and 387 is: 534.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    619.92 : 855.50 = 387 : x
  2. Step 2: Convert to fraction form
    619.92/855.50 = 387/x
  3. Step 3: Cross multiply
    619.92x = 855.50 × 387
  4. Step 4: Simplify right side
    619.92x = 331,076.57
  5. Step 5: Solve for x
    x = 331,076.57/619.92
  6. Step 6: Final answer
    x = 534.06

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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.