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Finding the Fourth Proportional to 129.12, 193.80 and 122.40

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Solution

The fourth proportional to 129.12, 193.80 and 122.40 is: 183.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    129.12 : 193.80 = 122.40 : x
  2. Step 2: Convert to fraction form
    129.12/193.80 = 122.40/x
  3. Step 3: Cross multiply
    129.12x = 193.80 × 122.40
  4. Step 4: Simplify right side
    129.12x = 23,721.12
  5. Step 5: Solve for x
    x = 23,721.12/129.12
  6. Step 6: Final answer
    x = 183.71

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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.