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Finding the Fourth Proportional to 206.39, 309.54 and 69.42

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Solution

The fourth proportional to 206.39, 309.54 and 69.42 is: 104.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    206.39 : 309.54 = 69.42 : x
  2. Step 2: Convert to fraction form
    206.39/309.54 = 69.42/x
  3. Step 3: Cross multiply
    206.39x = 309.54 × 69.42
  4. Step 4: Simplify right side
    206.39x = 21,488.27
  5. Step 5: Solve for x
    x = 21,488.27/206.39
  6. Step 6: Final answer
    x = 104.12

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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.