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Finding the Third Proportional to 421,638 and 553,580

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Solution

The third proportional to 421,638 and 553,580 is: 726,810.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    421,638 : 553,580 = 553,580 : x
  2. Step 2: Convert to fraction form
    421,638/553,580 = 553,580/x
  3. Step 3: Cross multiply
    421,638x = 553,580 × 553,580
  4. Step 4: Simplify right side
    421,638x = 306,450,816,400
  5. Step 5: Solve for x
    x = 306,450,816,400/421,638
  6. Step 6: Final answer
    x = 726,810.24

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Why These Related Problems?

These problems maintain the same ratio (1.31) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.