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Finding the Third Proportional to 427.78 and 687.02

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Solution

The third proportional to 427.78 and 687.02 is: 1,103.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.78 : 687.02 = 687.02 : x
  2. Step 2: Convert to fraction form
    427.78/687.02 = 687.02/x
  3. Step 3: Cross multiply
    427.78x = 687.02 × 687.02
  4. Step 4: Simplify right side
    427.78x = 472,001.20
  5. Step 5: Solve for x
    x = 472,001.20/427.78
  6. Step 6: Final answer
    x = 1,103.37

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Why These Related Problems?

These problems maintain the same ratio (1.61) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.