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Finding the Fourth Proportional to 206.39, 309.59 and 84.57

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Solution

The fourth proportional to 206.39, 309.59 and 84.57 is: 126.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    206.39 : 309.59 = 84.57 : x
  2. Step 2: Convert to fraction form
    206.39/309.59 = 84.57/x
  3. Step 3: Cross multiply
    206.39x = 309.59 × 84.57
  4. Step 4: Simplify right side
    206.39x = 26,182.24
  5. Step 5: Solve for x
    x = 26,182.24/206.39
  6. Step 6: Final answer
    x = 126.86

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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.