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Finding the Fourth Proportional to 427.34, 641.02 and 138.76

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Solution

The fourth proportional to 427.34, 641.02 and 138.76 is: 208.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.34 : 641.02 = 138.76 : x
  2. Step 2: Convert to fraction form
    427.34/641.02 = 138.76/x
  3. Step 3: Cross multiply
    427.34x = 641.02 × 138.76
  4. Step 4: Simplify right side
    427.34x = 88,947.94
  5. Step 5: Solve for x
    x = 88,947.94/427.34
  6. Step 6: Final answer
    x = 208.14

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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.