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Finding the Fourth Proportional to 426.31, 639 and 220.67

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Solution

The fourth proportional to 426.31, 639 and 220.67 is: 330.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.31 : 639 = 220.67 : x
  2. Step 2: Convert to fraction form
    426.31/639 = 220.67/x
  3. Step 3: Cross multiply
    426.31x = 639 × 220.67
  4. Step 4: Simplify right side
    426.31x = 141,004.94
  5. Step 5: Solve for x
    x = 141,004.94/426.31
  6. Step 6: Final answer
    x = 330.76

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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.