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Finding the Fourth Proportional to 256.57, 384.17 and 206.89

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Solution

The fourth proportional to 256.57, 384.17 and 206.89 is: 309.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    256.57 : 384.17 = 206.89 : x
  2. Step 2: Convert to fraction form
    256.57/384.17 = 206.89/x
  3. Step 3: Cross multiply
    256.57x = 384.17 × 206.89
  4. Step 4: Simplify right side
    256.57x = 79,478.94
  5. Step 5: Solve for x
    x = 79,478.94/256.57
  6. Step 6: Final answer
    x = 309.78

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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.