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Finding the Fourth Proportional to 425.91, 639.17 and 220.65

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Solution

The fourth proportional to 425.91, 639.17 and 220.65 is: 331.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    425.91 : 639.17 = 220.65 : x
  2. Step 2: Convert to fraction form
    425.91/639.17 = 220.65/x
  3. Step 3: Cross multiply
    425.91x = 639.17 × 220.65
  4. Step 4: Simplify right side
    425.91x = 141,032.86
  5. Step 5: Solve for x
    x = 141,032.86/425.91
  6. Step 6: Final answer
    x = 331.13

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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.