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Finding the Fourth Proportional to 206.21, 309.31 and 67.39

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Solution

The fourth proportional to 206.21, 309.31 and 67.39 is: 101.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    206.21 : 309.31 = 67.39 : x
  2. Step 2: Convert to fraction form
    206.21/309.31 = 67.39/x
  3. Step 3: Cross multiply
    206.21x = 309.31 × 67.39
  4. Step 4: Simplify right side
    206.21x = 20,843.46
  5. Step 5: Solve for x
    x = 20,843.46/206.21
  6. Step 6: Final answer
    x = 101.08

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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.