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Finding the Fourth Proportional to 80.47, 120.62 and 71.87

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Solution

The fourth proportional to 80.47, 120.62 and 71.87 is: 107.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.47 : 120.62 = 71.87 : x
  2. Step 2: Convert to fraction form
    80.47/120.62 = 71.87/x
  3. Step 3: Cross multiply
    80.47x = 120.62 × 71.87
  4. Step 4: Simplify right side
    80.47x = 8,668.96
  5. Step 5: Solve for x
    x = 8,668.96/80.47
  6. Step 6: Final answer
    x = 107.74

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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.