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Finding the Fourth Proportional to 256.91, 385.25 and 102.78

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Solution

The fourth proportional to 256.91, 385.25 and 102.78 is: 154.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    256.91 : 385.25 = 102.78 : x
  2. Step 2: Convert to fraction form
    256.91/385.25 = 102.78/x
  3. Step 3: Cross multiply
    256.91x = 385.25 × 102.78
  4. Step 4: Simplify right side
    256.91x = 39,595.48
  5. Step 5: Solve for x
    x = 39,595.48/256.91
  6. Step 6: Final answer
    x = 154.12

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.