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Finding the Fourth Proportional to 427.25, 640.72 and 207.98

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Solution

The fourth proportional to 427.25, 640.72 and 207.98 is: 311.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.25 : 640.72 = 207.98 : x
  2. Step 2: Convert to fraction form
    427.25/640.72 = 207.98/x
  3. Step 3: Cross multiply
    427.25x = 640.72 × 207.98
  4. Step 4: Simplify right side
    427.25x = 133,253.22
  5. Step 5: Solve for x
    x = 133,253.22/427.25
  6. Step 6: Final answer
    x = 311.88

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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.