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Finding the Fourth Proportional to 256.84, 385.23 and 85.84

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Solution

The fourth proportional to 256.84, 385.23 and 85.84 is: 128.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    256.84 : 385.23 = 85.84 : x
  2. Step 2: Convert to fraction form
    256.84/385.23 = 85.84/x
  3. Step 3: Cross multiply
    256.84x = 385.23 × 85.84
  4. Step 4: Simplify right side
    256.84x = 33,068.14
  5. Step 5: Solve for x
    x = 33,068.14/256.84
  6. Step 6: Final answer
    x = 128.75

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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.