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Finding the Fourth Proportional to 787.70, 1,087.39 and 577.90

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Solution

The fourth proportional to 787.70, 1,087.39 and 577.90 is: 797.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    787.70 : 1,087.39 = 577.90 : x
  2. Step 2: Convert to fraction form
    787.70/1,087.39 = 577.90/x
  3. Step 3: Cross multiply
    787.70x = 1,087.39 × 577.90
  4. Step 4: Simplify right side
    787.70x = 628,404.76
  5. Step 5: Solve for x
    x = 628,404.76/787.70
  6. Step 6: Final answer
    x = 797.77

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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.