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Finding the Fourth Proportional to 207.20, 309.98 and 138.39

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Solution

The fourth proportional to 207.20, 309.98 and 138.39 is: 207.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    207.20 : 309.98 = 138.39 : x
  2. Step 2: Convert to fraction form
    207.20/309.98 = 138.39/x
  3. Step 3: Cross multiply
    207.20x = 309.98 × 138.39
  4. Step 4: Simplify right side
    207.20x = 42,897.44
  5. Step 5: Solve for x
    x = 42,897.44/207.20
  6. Step 6: Final answer
    x = 207.04

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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.