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Finding the Fourth Proportional to 139.58, 191.15 and 137.78

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Solution

The fourth proportional to 139.58, 191.15 and 137.78 is: 188.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.58 : 191.15 = 137.78 : x
  2. Step 2: Convert to fraction form
    139.58/191.15 = 137.78/x
  3. Step 3: Cross multiply
    139.58x = 191.15 × 137.78
  4. Step 4: Simplify right side
    139.58x = 26,336.65
  5. Step 5: Solve for x
    x = 26,336.65/139.58
  6. Step 6: Final answer
    x = 188.68

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.