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Finding the Fourth Proportional to 657.84, 987.12 and 426.72

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Solution

The fourth proportional to 657.84, 987.12 and 426.72 is: 640.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    657.84 : 987.12 = 426.72 : x
  2. Step 2: Convert to fraction form
    657.84/987.12 = 426.72/x
  3. Step 3: Cross multiply
    657.84x = 987.12 × 426.72
  4. Step 4: Simplify right side
    657.84x = 421,223.85
  5. Step 5: Solve for x
    x = 421,223.85/657.84
  6. Step 6: Final answer
    x = 640.31

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.