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Finding the Fourth Proportional to 256.76, 385.26 and 128.52

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Solution

The fourth proportional to 256.76, 385.26 and 128.52 is: 192.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    256.76 : 385.26 = 128.52 : x
  2. Step 2: Convert to fraction form
    256.76/385.26 = 128.52/x
  3. Step 3: Cross multiply
    256.76x = 385.26 × 128.52
  4. Step 4: Simplify right side
    256.76x = 49,513.62
  5. Step 5: Solve for x
    x = 49,513.62/256.76
  6. Step 6: Final answer
    x = 192.84

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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.