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Finding the Fourth Proportional to 139.61, 209.42 and 131.91

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Solution

The fourth proportional to 139.61, 209.42 and 131.91 is: 197.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.61 : 209.42 = 131.91 : x
  2. Step 2: Convert to fraction form
    139.61/209.42 = 131.91/x
  3. Step 3: Cross multiply
    139.61x = 209.42 × 131.91
  4. Step 4: Simplify right side
    139.61x = 27,623.93
  5. Step 5: Solve for x
    x = 27,623.93/139.61
  6. Step 6: Final answer
    x = 197.87

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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.