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Finding the Fourth Proportional to 139.69, 209.19 and 67.38

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Solution

The fourth proportional to 139.69, 209.19 and 67.38 is: 100.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.69 : 209.19 = 67.38 : x
  2. Step 2: Convert to fraction form
    139.69/209.19 = 67.38/x
  3. Step 3: Cross multiply
    139.69x = 209.19 × 67.38
  4. Step 4: Simplify right side
    139.69x = 14,095.22
  5. Step 5: Solve for x
    x = 14,095.22/139.69
  6. Step 6: Final answer
    x = 100.90

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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.