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Finding the Third Proportional to 678.09 and 814.78

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Solution

The third proportional to 678.09 and 814.78 is: 979.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.09 : 814.78 = 814.78 : x
  2. Step 2: Convert to fraction form
    678.09/814.78 = 814.78/x
  3. Step 3: Cross multiply
    678.09x = 814.78 × 814.78
  4. Step 4: Simplify right side
    678.09x = 663,868.49
  5. Step 5: Solve for x
    x = 663,868.49/678.09
  6. Step 6: Final answer
    x = 979.02

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These problems maintain the same ratio (1.20) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.