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Finding the Fourth Proportional to 787.72, 1,087.02 and 456.12

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Solution

The fourth proportional to 787.72, 1,087.02 and 456.12 is: 629.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    787.72 : 1,087.02 = 456.12 : x
  2. Step 2: Convert to fraction form
    787.72/1,087.02 = 456.12/x
  3. Step 3: Cross multiply
    787.72x = 1,087.02 × 456.12
  4. Step 4: Simplify right side
    787.72x = 495,811.56
  5. Step 5: Solve for x
    x = 495,811.56/787.72
  6. Step 6: Final answer
    x = 629.43

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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.