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Finding the Fourth Proportional to 311.72, 468.05 and 287.42

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Solution

The fourth proportional to 311.72, 468.05 and 287.42 is: 431.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.72 : 468.05 = 287.42 : x
  2. Step 2: Convert to fraction form
    311.72/468.05 = 287.42/x
  3. Step 3: Cross multiply
    311.72x = 468.05 × 287.42
  4. Step 4: Simplify right side
    311.72x = 134,523.15
  5. Step 5: Solve for x
    x = 134,523.15/311.72
  6. Step 6: Final answer
    x = 431.56

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.