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Finding the Fourth Proportional to 256.56, 353.90 and 212.80

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Solution

The fourth proportional to 256.56, 353.90 and 212.80 is: 293.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    256.56 : 353.90 = 212.80 : x
  2. Step 2: Convert to fraction form
    256.56/353.90 = 212.80/x
  3. Step 3: Cross multiply
    256.56x = 353.90 × 212.80
  4. Step 4: Simplify right side
    256.56x = 75,309.92
  5. Step 5: Solve for x
    x = 75,309.92/256.56
  6. Step 6: Final answer
    x = 293.54

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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.