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Finding the Fourth Proportional to 129.20, 194.71 and 121.10

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Solution

The fourth proportional to 129.20, 194.71 and 121.10 is: 182.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    129.20 : 194.71 = 121.10 : x
  2. Step 2: Convert to fraction form
    129.20/194.71 = 121.10/x
  3. Step 3: Cross multiply
    129.20x = 194.71 × 121.10
  4. Step 4: Simplify right side
    129.20x = 23,578.78
  5. Step 5: Solve for x
    x = 23,578.78/129.20
  6. Step 6: Final answer
    x = 182.50

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.