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Finding the Fourth Proportional to 129.18, 178.03 and 105.76

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Solution

The fourth proportional to 129.18, 178.03 and 105.76 is: 145.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    129.18 : 178.03 = 105.76 : x
  2. Step 2: Convert to fraction form
    129.18/178.03 = 105.76/x
  3. Step 3: Cross multiply
    129.18x = 178.03 × 105.76
  4. Step 4: Simplify right side
    129.18x = 18,828.45
  5. Step 5: Solve for x
    x = 18,828.45/129.18
  6. Step 6: Final answer
    x = 145.75

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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.