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Finding the Fourth Proportional to 648.87, 971.33 and 428.66

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Solution

The fourth proportional to 648.87, 971.33 and 428.66 is: 641.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    648.87 : 971.33 = 428.66 : x
  2. Step 2: Convert to fraction form
    648.87/971.33 = 428.66/x
  3. Step 3: Cross multiply
    648.87x = 971.33 × 428.66
  4. Step 4: Simplify right side
    648.87x = 416,365.46
  5. Step 5: Solve for x
    x = 416,365.46/648.87
  6. Step 6: Final answer
    x = 641.68

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.