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Finding the Fourth Proportional to 139.49, 209.19 and 58.31

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Solution

The fourth proportional to 139.49, 209.19 and 58.31 is: 87.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.49 : 209.19 = 58.31 : x
  2. Step 2: Convert to fraction form
    139.49/209.19 = 58.31/x
  3. Step 3: Cross multiply
    139.49x = 209.19 × 58.31
  4. Step 4: Simplify right side
    139.49x = 12,198.61
  5. Step 5: Solve for x
    x = 12,198.61/139.49
  6. Step 6: Final answer
    x = 87.45

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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.