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Finding the Fourth Proportional to 425.70, 638.02 and 220.15

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Solution

The fourth proportional to 425.70, 638.02 and 220.15 is: 329.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    425.70 : 638.02 = 220.15 : x
  2. Step 2: Convert to fraction form
    425.70/638.02 = 220.15/x
  3. Step 3: Cross multiply
    425.70x = 638.02 × 220.15
  4. Step 4: Simplify right side
    425.70x = 140,457.96
  5. Step 5: Solve for x
    x = 140,457.96/425.70
  6. Step 6: Final answer
    x = 329.95

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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.