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Finding the Fourth Proportional to 427.44, 641.26 and 138.90

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Solution

The fourth proportional to 427.44, 641.26 and 138.90 is: 208.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.44 : 641.26 = 138.90 : x
  2. Step 2: Convert to fraction form
    427.44/641.26 = 138.90/x
  3. Step 3: Cross multiply
    427.44x = 641.26 × 138.90
  4. Step 4: Simplify right side
    427.44x = 89,071.01
  5. Step 5: Solve for x
    x = 89,071.01/427.44
  6. Step 6: Final answer
    x = 208.38

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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.