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Finding the Fourth Proportional to 311.78, 467.64 and 129.12

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Solution

The fourth proportional to 311.78, 467.64 and 129.12 is: 193.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.78 : 467.64 = 129.12 : x
  2. Step 2: Convert to fraction form
    311.78/467.64 = 129.12/x
  3. Step 3: Cross multiply
    311.78x = 467.64 × 129.12
  4. Step 4: Simplify right side
    311.78x = 60,381.68
  5. Step 5: Solve for x
    x = 60,381.68/311.78
  6. Step 6: Final answer
    x = 193.67

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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.