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Finding the Third Proportional to 256.92 and 399.09

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Solution

The third proportional to 256.92 and 399.09 is: 619.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    256.92 : 399.09 = 399.09 : x
  2. Step 2: Convert to fraction form
    256.92/399.09 = 399.09/x
  3. Step 3: Cross multiply
    256.92x = 399.09 × 399.09
  4. Step 4: Simplify right side
    256.92x = 159,275.82
  5. Step 5: Solve for x
    x = 159,275.82/256.92
  6. Step 6: Final answer
    x = 619.94

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Why These Related Problems?

These problems maintain the same ratio (1.55) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.