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Finding the Fourth Proportional to 787.52, 1,086.78 and 438.20

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Solution

The fourth proportional to 787.52, 1,086.78 and 438.20 is: 604.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    787.52 : 1,086.78 = 438.20 : x
  2. Step 2: Convert to fraction form
    787.52/1,086.78 = 438.20/x
  3. Step 3: Cross multiply
    787.52x = 1,086.78 × 438.20
  4. Step 4: Simplify right side
    787.52x = 476,227.00
  5. Step 5: Solve for x
    x = 476,227.00/787.52
  6. Step 6: Final answer
    x = 604.72

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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.