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Finding the Third Proportional to 821.55 and 1,781.21

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Solution

The third proportional to 821.55 and 1,781.21 is: 3,861.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    821.55 : 1,781.21 = 1,781.21 : x
  2. Step 2: Convert to fraction form
    821.55/1,781.21 = 1,781.21/x
  3. Step 3: Cross multiply
    821.55x = 1,781.21 × 1,781.21
  4. Step 4: Simplify right side
    821.55x = 3,172,705.45
  5. Step 5: Solve for x
    x = 3,172,705.45/821.55
  6. Step 6: Final answer
    x = 3,861.86

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Why These Related Problems?

These problems maintain the same ratio (2.17) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.