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Finding the Fourth Proportional to 725.48, 1,087.12 and 378.90

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Solution

The fourth proportional to 725.48, 1,087.12 and 378.90 is: 567.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    725.48 : 1,087.12 = 378.90 : x
  2. Step 2: Convert to fraction form
    725.48/1,087.12 = 378.90/x
  3. Step 3: Cross multiply
    725.48x = 1,087.12 × 378.90
  4. Step 4: Simplify right side
    725.48x = 411,909.77
  5. Step 5: Solve for x
    x = 411,909.77/725.48
  6. Step 6: Final answer
    x = 567.78

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.