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Finding the Fourth Proportional to 408, 612.16 and 256

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Solution

The fourth proportional to 408, 612.16 and 256 is: 384.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    408 : 612.16 = 256 : x
  2. Step 2: Convert to fraction form
    408/612.16 = 256/x
  3. Step 3: Cross multiply
    408x = 612.16 × 256
  4. Step 4: Simplify right side
    408x = 156,712.96
  5. Step 5: Solve for x
    x = 156,712.96/408
  6. Step 6: Final answer
    x = 384.10

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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.