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Finding the Fourth Proportional to 620.31, 855.85 and 488.91

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Solution

The fourth proportional to 620.31, 855.85 and 488.91 is: 674.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.31 : 855.85 = 488.91 : x
  2. Step 2: Convert to fraction form
    620.31/855.85 = 488.91/x
  3. Step 3: Cross multiply
    620.31x = 855.85 × 488.91
  4. Step 4: Simplify right side
    620.31x = 418,433.62
  5. Step 5: Solve for x
    x = 418,433.62/620.31
  6. Step 6: Final answer
    x = 674.56

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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.