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Finding the Fourth Proportional to 129.11, 178.22 and 90.23

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Solution

The fourth proportional to 129.11, 178.22 and 90.23 is: 124.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    129.11 : 178.22 = 90.23 : x
  2. Step 2: Convert to fraction form
    129.11/178.22 = 90.23/x
  3. Step 3: Cross multiply
    129.11x = 178.22 × 90.23
  4. Step 4: Simplify right side
    129.11x = 16,080.79
  5. Step 5: Solve for x
    x = 16,080.79/129.11
  6. Step 6: Final answer
    x = 124.55

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.