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Finding the Fourth Proportional to 427.26, 640.91 and 208.09

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Solution

The fourth proportional to 427.26, 640.91 and 208.09 is: 312.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.26 : 640.91 = 208.09 : x
  2. Step 2: Convert to fraction form
    427.26/640.91 = 208.09/x
  3. Step 3: Cross multiply
    427.26x = 640.91 × 208.09
  4. Step 4: Simplify right side
    427.26x = 133,365.88
  5. Step 5: Solve for x
    x = 133,365.88/427.26
  6. Step 6: Final answer
    x = 312.14

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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.