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Finding the Fourth Proportional to 256.65, 385.17 and 205.74

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Solution

The fourth proportional to 256.65, 385.17 and 205.74 is: 308.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    256.65 : 385.17 = 205.74 : x
  2. Step 2: Convert to fraction form
    256.65/385.17 = 205.74/x
  3. Step 3: Cross multiply
    256.65x = 385.17 × 205.74
  4. Step 4: Simplify right side
    256.65x = 79,244.88
  5. Step 5: Solve for x
    x = 79,244.88/256.65
  6. Step 6: Final answer
    x = 308.77

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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.