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Finding the Fourth Proportional to 256.12, 353.45 and 139.70

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Solution

The fourth proportional to 256.12, 353.45 and 139.70 is: 192.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    256.12 : 353.45 = 139.70 : x
  2. Step 2: Convert to fraction form
    256.12/353.45 = 139.70/x
  3. Step 3: Cross multiply
    256.12x = 353.45 × 139.70
  4. Step 4: Simplify right side
    256.12x = 49,376.97
  5. Step 5: Solve for x
    x = 49,376.97/256.12
  6. Step 6: Final answer
    x = 192.79

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.