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Finding the Fourth Proportional to 206.42, 309.67 and 138.38

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Solution

The fourth proportional to 206.42, 309.67 and 138.38 is: 207.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    206.42 : 309.67 = 138.38 : x
  2. Step 2: Convert to fraction form
    206.42/309.67 = 138.38/x
  3. Step 3: Cross multiply
    206.42x = 309.67 × 138.38
  4. Step 4: Simplify right side
    206.42x = 42,850.24
  5. Step 5: Solve for x
    x = 42,850.24/206.42
  6. Step 6: Final answer
    x = 207.59

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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.