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Finding the Fourth Proportional to 256.87, 385.28 and 102.79

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Solution

The fourth proportional to 256.87, 385.28 and 102.79 is: 154.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    256.87 : 385.28 = 102.79 : x
  2. Step 2: Convert to fraction form
    256.87/385.28 = 102.79/x
  3. Step 3: Cross multiply
    256.87x = 385.28 × 102.79
  4. Step 4: Simplify right side
    256.87x = 39,602.42
  5. Step 5: Solve for x
    x = 39,602.42/256.87
  6. Step 6: Final answer
    x = 154.17

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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.