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Finding the Fourth Proportional to 129.52, 178.71 and 71.30

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Solution

The fourth proportional to 129.52, 178.71 and 71.30 is: 98.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    129.52 : 178.71 = 71.30 : x
  2. Step 2: Convert to fraction form
    129.52/178.71 = 71.30/x
  3. Step 3: Cross multiply
    129.52x = 178.71 × 71.30
  4. Step 4: Simplify right side
    129.52x = 12,742.20
  5. Step 5: Solve for x
    x = 12,742.20/129.52
  6. Step 6: Final answer
    x = 98.38

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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.