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Finding the Fourth Proportional to 217.92, 300.68 and 129.40

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Solution

The fourth proportional to 217.92, 300.68 and 129.40 is: 178.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    217.92 : 300.68 = 129.40 : x
  2. Step 2: Convert to fraction form
    217.92/300.68 = 129.40/x
  3. Step 3: Cross multiply
    217.92x = 300.68 × 129.40
  4. Step 4: Simplify right side
    217.92x = 38,907.08
  5. Step 5: Solve for x
    x = 38,907.08/217.92
  6. Step 6: Final answer
    x = 178.54

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.