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Finding the Fourth Proportional to 311.76, 430.32 and 213.76

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Solution

The fourth proportional to 311.76, 430.32 and 213.76 is: 295.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.76 : 430.32 = 213.76 : x
  2. Step 2: Convert to fraction form
    311.76/430.32 = 213.76/x
  3. Step 3: Cross multiply
    311.76x = 430.32 × 213.76
  4. Step 4: Simplify right side
    311.76x = 91,985.20
  5. Step 5: Solve for x
    x = 91,985.20/311.76
  6. Step 6: Final answer
    x = 295.05

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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.