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Finding the Fourth Proportional to 312.35, 431.20 and 201.88

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Solution

The fourth proportional to 312.35, 431.20 and 201.88 is: 278.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    312.35 : 431.20 = 201.88 : x
  2. Step 2: Convert to fraction form
    312.35/431.20 = 201.88/x
  3. Step 3: Cross multiply
    312.35x = 431.20 × 201.88
  4. Step 4: Simplify right side
    312.35x = 87,052.85
  5. Step 5: Solve for x
    x = 87,052.85/312.35
  6. Step 6: Final answer
    x = 278.71

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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.