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Finding the Fourth Proportional to 129.81, 178.97 and 98.76

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Solution

The fourth proportional to 129.81, 178.97 and 98.76 is: 136.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    129.81 : 178.97 = 98.76 : x
  2. Step 2: Convert to fraction form
    129.81/178.97 = 98.76/x
  3. Step 3: Cross multiply
    129.81x = 178.97 × 98.76
  4. Step 4: Simplify right side
    129.81x = 17,674.58
  5. Step 5: Solve for x
    x = 17,674.58/129.81
  6. Step 6: Final answer
    x = 136.16

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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.