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Finding the Third Proportional to 280 and 620

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Solution

The third proportional to 280 and 620 is: 1,372.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    280 : 620 = 620 : x
  2. Step 2: Convert to fraction form
    280/620 = 620/x
  3. Step 3: Cross multiply
    280x = 620 × 620
  4. Step 4: Simplify right side
    280x = 384,400
  5. Step 5: Solve for x
    x = 384,400/280
  6. Step 6: Final answer
    x = 1,372.86

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Why These Related Problems?

These problems maintain the same ratio (2.21) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.