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Finding the Fourth Proportional to 207.49, 310.92 and 138.78

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Solution

The fourth proportional to 207.49, 310.92 and 138.78 is: 207.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    207.49 : 310.92 = 138.78 : x
  2. Step 2: Convert to fraction form
    207.49/310.92 = 138.78/x
  3. Step 3: Cross multiply
    207.49x = 310.92 × 138.78
  4. Step 4: Simplify right side
    207.49x = 43,149.48
  5. Step 5: Solve for x
    x = 43,149.48/207.49
  6. Step 6: Final answer
    x = 207.96

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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.