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Finding the Fourth Proportional to 428.20, 642.06 and 223

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Solution

The fourth proportional to 428.20, 642.06 and 223 is: 334.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.20 : 642.06 = 223 : x
  2. Step 2: Convert to fraction form
    428.20/642.06 = 223/x
  3. Step 3: Cross multiply
    428.20x = 642.06 × 223
  4. Step 4: Simplify right side
    428.20x = 143,179.38
  5. Step 5: Solve for x
    x = 143,179.38/428.20
  6. Step 6: Final answer
    x = 334.38

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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.