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Finding the Fourth Proportional to 138.32, 206.38 and 129.08

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Solution

The fourth proportional to 138.32, 206.38 and 129.08 is: 192.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.32 : 206.38 = 129.08 : x
  2. Step 2: Convert to fraction form
    138.32/206.38 = 129.08/x
  3. Step 3: Cross multiply
    138.32x = 206.38 × 129.08
  4. Step 4: Simplify right side
    138.32x = 26,639.53
  5. Step 5: Solve for x
    x = 26,639.53/138.32
  6. Step 6: Final answer
    x = 192.59

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.