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Finding the Fourth Proportional to 311.52, 429.90 and 201.20

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Solution

The fourth proportional to 311.52, 429.90 and 201.20 is: 277.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.52 : 429.90 = 201.20 : x
  2. Step 2: Convert to fraction form
    311.52/429.90 = 201.20/x
  3. Step 3: Cross multiply
    311.52x = 429.90 × 201.20
  4. Step 4: Simplify right side
    311.52x = 86,495.88
  5. Step 5: Solve for x
    x = 86,495.88/311.52
  6. Step 6: Final answer
    x = 277.66

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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.