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Finding the Fourth Proportional to 640.46, 884.57 and 420.39

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Solution

The fourth proportional to 640.46, 884.57 and 420.39 is: 580.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.46 : 884.57 = 420.39 : x
  2. Step 2: Convert to fraction form
    640.46/884.57 = 420.39/x
  3. Step 3: Cross multiply
    640.46x = 884.57 × 420.39
  4. Step 4: Simplify right side
    640.46x = 371,864.38
  5. Step 5: Solve for x
    x = 371,864.38/640.46
  6. Step 6: Final answer
    x = 580.62

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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.