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Finding the Fourth Proportional to 311.78, 430.34 and 213.50

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Solution

The fourth proportional to 311.78, 430.34 and 213.50 is: 294.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.78 : 430.34 = 213.50 : x
  2. Step 2: Convert to fraction form
    311.78/430.34 = 213.50/x
  3. Step 3: Cross multiply
    311.78x = 430.34 × 213.50
  4. Step 4: Simplify right side
    311.78x = 91,877.60
  5. Step 5: Solve for x
    x = 91,877.60/311.78
  6. Step 6: Final answer
    x = 294.68

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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.