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Finding the Third Proportional to 640.13 and 861.05

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Solution

The third proportional to 640.13 and 861.05 is: 1,158.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    640.13 : 861.05 = 861.05 : x
  2. Step 2: Convert to fraction form
    640.13/861.05 = 861.05/x
  3. Step 3: Cross multiply
    640.13x = 861.05 × 861.05
  4. Step 4: Simplify right side
    640.13x = 741,401.72
  5. Step 5: Solve for x
    x = 741,401.72/640.13
  6. Step 6: Final answer
    x = 1,158.21

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These problems maintain the same ratio (1.35) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.