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Finding the Third Proportional to 685 and 772

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Solution

The third proportional to 685 and 772 is: 870.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    685 : 772 = 772 : x
  2. Step 2: Convert to fraction form
    685/772 = 772/x
  3. Step 3: Cross multiply
    685x = 772 × 772
  4. Step 4: Simplify right side
    685x = 595,984
  5. Step 5: Solve for x
    x = 595,984/685
  6. Step 6: Final answer
    x = 870.05

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Why These Related Problems?

These problems maintain the same ratio (1.13) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.