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Finding the Fourth Proportional to 256.89, 385.30 and 213.83

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Solution

The fourth proportional to 256.89, 385.30 and 213.83 is: 320.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    256.89 : 385.30 = 213.83 : x
  2. Step 2: Convert to fraction form
    256.89/385.30 = 213.83/x
  3. Step 3: Cross multiply
    256.89x = 385.30 × 213.83
  4. Step 4: Simplify right side
    256.89x = 82,388.70
  5. Step 5: Solve for x
    x = 82,388.70/256.89
  6. Step 6: Final answer
    x = 320.72

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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.