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Finding the Fourth Proportional to 640.38, 877.97 and 628.71

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Solution

The fourth proportional to 640.38, 877.97 and 628.71 is: 861.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.38 : 877.97 = 628.71 : x
  2. Step 2: Convert to fraction form
    640.38/877.97 = 628.71/x
  3. Step 3: Cross multiply
    640.38x = 877.97 × 628.71
  4. Step 4: Simplify right side
    640.38x = 551,981.87
  5. Step 5: Solve for x
    x = 551,981.87/640.38
  6. Step 6: Final answer
    x = 861.96

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.