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Finding the Fourth Proportional to 129.87, 179.31 and 90.63

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Solution

The fourth proportional to 129.87, 179.31 and 90.63 is: 125.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    129.87 : 179.31 = 90.63 : x
  2. Step 2: Convert to fraction form
    129.87/179.31 = 90.63/x
  3. Step 3: Cross multiply
    129.87x = 179.31 × 90.63
  4. Step 4: Simplify right side
    129.87x = 16,250.87
  5. Step 5: Solve for x
    x = 16,250.87/129.87
  6. Step 6: Final answer
    x = 125.13

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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.