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Finding the Fourth Proportional to 619.76, 855.14 and 383.90

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Solution

The fourth proportional to 619.76, 855.14 and 383.90 is: 529.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    619.76 : 855.14 = 383.90 : x
  2. Step 2: Convert to fraction form
    619.76/855.14 = 383.90/x
  3. Step 3: Cross multiply
    619.76x = 855.14 × 383.90
  4. Step 4: Simplify right side
    619.76x = 328,282.05
  5. Step 5: Solve for x
    x = 328,282.05/619.76
  6. Step 6: Final answer
    x = 529.70

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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.