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Finding the Fourth Proportional to 129.28, 193.77 and 90.71

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Solution

The fourth proportional to 129.28, 193.77 and 90.71 is: 135.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    129.28 : 193.77 = 90.71 : x
  2. Step 2: Convert to fraction form
    129.28/193.77 = 90.71/x
  3. Step 3: Cross multiply
    129.28x = 193.77 × 90.71
  4. Step 4: Simplify right side
    129.28x = 17,576.88
  5. Step 5: Solve for x
    x = 17,576.88/129.28
  6. Step 6: Final answer
    x = 135.96

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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.