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Finding the Fourth Proportional to 206.11, 309.07 and 90.55

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Solution

The fourth proportional to 206.11, 309.07 and 90.55 is: 135.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    206.11 : 309.07 = 90.55 : x
  2. Step 2: Convert to fraction form
    206.11/309.07 = 90.55/x
  3. Step 3: Cross multiply
    206.11x = 309.07 × 90.55
  4. Step 4: Simplify right side
    206.11x = 27,986.29
  5. Step 5: Solve for x
    x = 27,986.29/206.11
  6. Step 6: Final answer
    x = 135.78

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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.