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Finding the Fourth Proportional to 620.62, 856.78 and 487.92

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Solution

The fourth proportional to 620.62, 856.78 and 487.92 is: 673.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.62 : 856.78 = 487.92 : x
  2. Step 2: Convert to fraction form
    620.62/856.78 = 487.92/x
  3. Step 3: Cross multiply
    620.62x = 856.78 × 487.92
  4. Step 4: Simplify right side
    620.62x = 418,039.80
  5. Step 5: Solve for x
    x = 418,039.80/620.62
  6. Step 6: Final answer
    x = 673.59

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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.