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Finding the Fourth Proportional to 787.12, 1,087.01 and 648.61

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Solution

The fourth proportional to 787.12, 1,087.01 and 648.61 is: 895.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    787.12 : 1,087.01 = 648.61 : x
  2. Step 2: Convert to fraction form
    787.12/1,087.01 = 648.61/x
  3. Step 3: Cross multiply
    787.12x = 1,087.01 × 648.61
  4. Step 4: Simplify right side
    787.12x = 705,036.88
  5. Step 5: Solve for x
    x = 705,036.88/787.12
  6. Step 6: Final answer
    x = 895.72

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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.