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Finding the Fourth Proportional to 640.20, 880.56 and 520.68

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Solution

The fourth proportional to 640.20, 880.56 and 520.68 is: 716.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.20 : 880.56 = 520.68 : x
  2. Step 2: Convert to fraction form
    640.20/880.56 = 520.68/x
  3. Step 3: Cross multiply
    640.20x = 880.56 × 520.68
  4. Step 4: Simplify right side
    640.20x = 458,489.98
  5. Step 5: Solve for x
    x = 458,489.98/640.20
  6. Step 6: Final answer
    x = 716.17

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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.