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Finding the Fourth Proportional to 256, 384.10 and 85

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Solution

The fourth proportional to 256, 384.10 and 85 is: 127.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    256 : 384.10 = 85 : x
  2. Step 2: Convert to fraction form
    256/384.10 = 85/x
  3. Step 3: Cross multiply
    256x = 384.10 × 85
  4. Step 4: Simplify right side
    256x = 32,648.50
  5. Step 5: Solve for x
    x = 32,648.50/256
  6. Step 6: Final answer
    x = 127.53

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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.