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Finding the Fourth Proportional to 256.64, 385.05 and 119.78

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Solution

The fourth proportional to 256.64, 385.05 and 119.78 is: 179.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    256.64 : 385.05 = 119.78 : x
  2. Step 2: Convert to fraction form
    256.64/385.05 = 119.78/x
  3. Step 3: Cross multiply
    256.64x = 385.05 × 119.78
  4. Step 4: Simplify right side
    256.64x = 46,121.26
  5. Step 5: Solve for x
    x = 46,121.26/256.64
  6. Step 6: Final answer
    x = 179.71

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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.