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Finding the Third Proportional to 128,728 and 198,930

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Solution

The third proportional to 128,728 and 198,930 is: 307,416.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    128,728 : 198,930 = 198,930 : x
  2. Step 2: Convert to fraction form
    128,728/198,930 = 198,930/x
  3. Step 3: Cross multiply
    128,728x = 198,930 × 198,930
  4. Step 4: Simplify right side
    128,728x = 39,573,144,900
  5. Step 5: Solve for x
    x = 39,573,144,900/128,728
  6. Step 6: Final answer
    x = 307,416.76

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Why These Related Problems?

These problems maintain the same ratio (1.55) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.