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Finding the Fourth Proportional to 711.20, 981.43 and 396.45

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Solution

The fourth proportional to 711.20, 981.43 and 396.45 is: 547.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    711.20 : 981.43 = 396.45 : x
  2. Step 2: Convert to fraction form
    711.20/981.43 = 396.45/x
  3. Step 3: Cross multiply
    711.20x = 981.43 × 396.45
  4. Step 4: Simplify right side
    711.20x = 389,087.92
  5. Step 5: Solve for x
    x = 389,087.92/711.20
  6. Step 6: Final answer
    x = 547.09

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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.