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Finding the Fourth Proportional to 129.18, 177.45 and 122.40

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Solution

The fourth proportional to 129.18, 177.45 and 122.40 is: 168.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    129.18 : 177.45 = 122.40 : x
  2. Step 2: Convert to fraction form
    129.18/177.45 = 122.40/x
  3. Step 3: Cross multiply
    129.18x = 177.45 × 122.40
  4. Step 4: Simplify right side
    129.18x = 21,719.88
  5. Step 5: Solve for x
    x = 21,719.88/129.18
  6. Step 6: Final answer
    x = 168.14

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.