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Finding the Fourth Proportional to 139.21, 191.82 and 97.72

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Solution

The fourth proportional to 139.21, 191.82 and 97.72 is: 134.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.21 : 191.82 = 97.72 : x
  2. Step 2: Convert to fraction form
    139.21/191.82 = 97.72/x
  3. Step 3: Cross multiply
    139.21x = 191.82 × 97.72
  4. Step 4: Simplify right side
    139.21x = 18,744.65
  5. Step 5: Solve for x
    x = 18,744.65/139.21
  6. Step 6: Final answer
    x = 134.65

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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.