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Finding the Fourth Proportional to 425.69, 639.13 and 220.41

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Solution

The fourth proportional to 425.69, 639.13 and 220.41 is: 330.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    425.69 : 639.13 = 220.41 : x
  2. Step 2: Convert to fraction form
    425.69/639.13 = 220.41/x
  3. Step 3: Cross multiply
    425.69x = 639.13 × 220.41
  4. Step 4: Simplify right side
    425.69x = 140,870.64
  5. Step 5: Solve for x
    x = 140,870.64/425.69
  6. Step 6: Final answer
    x = 330.92

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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.