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Finding the Third Proportional to 128,309 and 308,721

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Solution

The third proportional to 128,309 and 308,721 is: 742,805.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    128,309 : 308,721 = 308,721 : x
  2. Step 2: Convert to fraction form
    128,309/308,721 = 308,721/x
  3. Step 3: Cross multiply
    128,309x = 308,721 × 308,721
  4. Step 4: Simplify right side
    128,309x = 95,308,655,841
  5. Step 5: Solve for x
    x = 95,308,655,841/128,309
  6. Step 6: Final answer
    x = 742,805.69

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Why These Related Problems?

These problems maintain the same ratio (2.41) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.