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Finding the Fourth Proportional to 249.20, 343.87 and 138.65

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Solution

The fourth proportional to 249.20, 343.87 and 138.65 is: 191.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    249.20 : 343.87 = 138.65 : x
  2. Step 2: Convert to fraction form
    249.20/343.87 = 138.65/x
  3. Step 3: Cross multiply
    249.20x = 343.87 × 138.65
  4. Step 4: Simplify right side
    249.20x = 47,677.58
  5. Step 5: Solve for x
    x = 47,677.58/249.20
  6. Step 6: Final answer
    x = 191.32

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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.