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Finding the Third Proportional to 128,790 and 287,712

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Solution

The third proportional to 128,790 and 287,712 is: 642,737.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    128,790 : 287,712 = 287,712 : x
  2. Step 2: Convert to fraction form
    128,790/287,712 = 287,712/x
  3. Step 3: Cross multiply
    128,790x = 287,712 × 287,712
  4. Step 4: Simplify right side
    128,790x = 82,778,194,944
  5. Step 5: Solve for x
    x = 82,778,194,944/128,790
  6. Step 6: Final answer
    x = 642,737.75

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Why These Related Problems?

These problems maintain the same ratio (2.23) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.