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Finding the Fourth Proportional to 129.78, 194.40 and 129.60

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Solution

The fourth proportional to 129.78, 194.40 and 129.60 is: 194.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    129.78 : 194.40 = 129.60 : x
  2. Step 2: Convert to fraction form
    129.78/194.40 = 129.60/x
  3. Step 3: Cross multiply
    129.78x = 194.40 × 129.60
  4. Step 4: Simplify right side
    129.78x = 25,194.24
  5. Step 5: Solve for x
    x = 25,194.24/129.78
  6. Step 6: Final answer
    x = 194.13

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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.