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Finding the Fourth Proportional to 249.09, 343.78 and 138.60

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Solution

The fourth proportional to 249.09, 343.78 and 138.60 is: 191.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    249.09 : 343.78 = 138.60 : x
  2. Step 2: Convert to fraction form
    249.09/343.78 = 138.60/x
  3. Step 3: Cross multiply
    249.09x = 343.78 × 138.60
  4. Step 4: Simplify right side
    249.09x = 47,647.91
  5. Step 5: Solve for x
    x = 47,647.91/249.09
  6. Step 6: Final answer
    x = 191.29

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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.