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Finding the Fourth Proportional to 206.21, 309.32 and 69.20

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Solution

The fourth proportional to 206.21, 309.32 and 69.20 is: 103.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    206.21 : 309.32 = 69.20 : x
  2. Step 2: Convert to fraction form
    206.21/309.32 = 69.20/x
  3. Step 3: Cross multiply
    206.21x = 309.32 × 69.20
  4. Step 4: Simplify right side
    206.21x = 21,404.94
  5. Step 5: Solve for x
    x = 21,404.94/206.21
  6. Step 6: Final answer
    x = 103.80

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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.