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Finding the Fourth Proportional to 129.25, 178.43 and 90.51

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Solution

The fourth proportional to 129.25, 178.43 and 90.51 is: 124.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    129.25 : 178.43 = 90.51 : x
  2. Step 2: Convert to fraction form
    129.25/178.43 = 90.51/x
  3. Step 3: Cross multiply
    129.25x = 178.43 × 90.51
  4. Step 4: Simplify right side
    129.25x = 16,149.70
  5. Step 5: Solve for x
    x = 16,149.70/129.25
  6. Step 6: Final answer
    x = 124.95

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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.