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Finding the Fourth Proportional to 427.09, 640.91 and 423.61

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Solution

The fourth proportional to 427.09, 640.91 and 423.61 is: 635.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.09 : 640.91 = 423.61 : x
  2. Step 2: Convert to fraction form
    427.09/640.91 = 423.61/x
  3. Step 3: Cross multiply
    427.09x = 640.91 × 423.61
  4. Step 4: Simplify right side
    427.09x = 271,495.89
  5. Step 5: Solve for x
    x = 271,495.89/427.09
  6. Step 6: Final answer
    x = 635.69

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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.