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Finding the Fourth Proportional to 787.11, 1,086.15 and 455.56

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Solution

The fourth proportional to 787.11, 1,086.15 and 455.56 is: 628.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    787.11 : 1,086.15 = 455.56 : x
  2. Step 2: Convert to fraction form
    787.11/1,086.15 = 455.56/x
  3. Step 3: Cross multiply
    787.11x = 1,086.15 × 455.56
  4. Step 4: Simplify right side
    787.11x = 494,809.56
  5. Step 5: Solve for x
    x = 494,809.56/787.11
  6. Step 6: Final answer
    x = 628.64

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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.