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Finding the Third Proportional to 1,680 and 3,960

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Solution

The third proportional to 1,680 and 3,960 is: 9,334.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,680 : 3,960 = 3,960 : x
  2. Step 2: Convert to fraction form
    1,680/3,960 = 3,960/x
  3. Step 3: Cross multiply
    1,680x = 3,960 × 3,960
  4. Step 4: Simplify right side
    1,680x = 15,681,600
  5. Step 5: Solve for x
    x = 15,681,600/1,680
  6. Step 6: Final answer
    x = 9,334.29

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Why These Related Problems?

These problems maintain the same ratio (2.36) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.