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Finding the Fourth Proportional to 256.94, 385.41 and 85.94

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Solution

The fourth proportional to 256.94, 385.41 and 85.94 is: 128.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    256.94 : 385.41 = 85.94 : x
  2. Step 2: Convert to fraction form
    256.94/385.41 = 85.94/x
  3. Step 3: Cross multiply
    256.94x = 385.41 × 85.94
  4. Step 4: Simplify right side
    256.94x = 33,122.14
  5. Step 5: Solve for x
    x = 33,122.14/256.94
  6. Step 6: Final answer
    x = 128.91

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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.