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Finding the Fourth Proportional to 129.28, 193.92 and 57.20

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Solution

The fourth proportional to 129.28, 193.92 and 57.20 is: 85.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    129.28 : 193.92 = 57.20 : x
  2. Step 2: Convert to fraction form
    129.28/193.92 = 57.20/x
  3. Step 3: Cross multiply
    129.28x = 193.92 × 57.20
  4. Step 4: Simplify right side
    129.28x = 11,092.22
  5. Step 5: Solve for x
    x = 11,092.22/129.28
  6. Step 6: Final answer
    x = 85.80

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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.