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Finding the Fourth Proportional to 129.16, 193.76 and 77.81

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Solution

The fourth proportional to 129.16, 193.76 and 77.81 is: 116.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    129.16 : 193.76 = 77.81 : x
  2. Step 2: Convert to fraction form
    129.16/193.76 = 77.81/x
  3. Step 3: Cross multiply
    129.16x = 193.76 × 77.81
  4. Step 4: Simplify right side
    129.16x = 15,076.08
  5. Step 5: Solve for x
    x = 15,076.08/129.16
  6. Step 6: Final answer
    x = 116.73

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.