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Finding the Fourth Proportional to 256.29, 384.45 and 80.58

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Solution

The fourth proportional to 256.29, 384.45 and 80.58 is: 120.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    256.29 : 384.45 = 80.58 : x
  2. Step 2: Convert to fraction form
    256.29/384.45 = 80.58/x
  3. Step 3: Cross multiply
    256.29x = 384.45 × 80.58
  4. Step 4: Simplify right side
    256.29x = 30,978.98
  5. Step 5: Solve for x
    x = 30,978.98/256.29
  6. Step 6: Final answer
    x = 120.87

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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.