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Finding the Third Proportional to 256.78 and 400.22

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Solution

The third proportional to 256.78 and 400.22 is: 623.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    256.78 : 400.22 = 400.22 : x
  2. Step 2: Convert to fraction form
    256.78/400.22 = 400.22/x
  3. Step 3: Cross multiply
    256.78x = 400.22 × 400.22
  4. Step 4: Simplify right side
    256.78x = 160,175.05
  5. Step 5: Solve for x
    x = 160,175.05/256.78
  6. Step 6: Final answer
    x = 623.78

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Why These Related Problems?

These problems maintain the same ratio (1.56) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.