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Finding the Fourth Proportional to 787.16, 1,086.28 and 455.64

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Solution

The fourth proportional to 787.16, 1,086.28 and 455.64 is: 628.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    787.16 : 1,086.28 = 455.64 : x
  2. Step 2: Convert to fraction form
    787.16/1,086.28 = 455.64/x
  3. Step 3: Cross multiply
    787.16x = 1,086.28 × 455.64
  4. Step 4: Simplify right side
    787.16x = 494,952.62
  5. Step 5: Solve for x
    x = 494,952.62/787.16
  6. Step 6: Final answer
    x = 628.78

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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.