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Finding the Fourth Proportional to 257.20, 354.78 and 201.85

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Solution

The fourth proportional to 257.20, 354.78 and 201.85 is: 278.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    257.20 : 354.78 = 201.85 : x
  2. Step 2: Convert to fraction form
    257.20/354.78 = 201.85/x
  3. Step 3: Cross multiply
    257.20x = 354.78 × 201.85
  4. Step 4: Simplify right side
    257.20x = 71,612.34
  5. Step 5: Solve for x
    x = 71,612.34/257.20
  6. Step 6: Final answer
    x = 278.43

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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.