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Finding the Third Proportional to 643.50 and 907.31

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Solution

The third proportional to 643.50 and 907.31 is: 1,279.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.50 : 907.31 = 907.31 : x
  2. Step 2: Convert to fraction form
    643.50/907.31 = 907.31/x
  3. Step 3: Cross multiply
    643.50x = 907.31 × 907.31
  4. Step 4: Simplify right side
    643.50x = 823,215.97
  5. Step 5: Solve for x
    x = 823,215.97/643.50
  6. Step 6: Final answer
    x = 1,279.28

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Why These Related Problems?

These problems maintain the same ratio (1.41) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.