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Finding the Fourth Proportional to 425.39, 638.18 and 206.18

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Solution

The fourth proportional to 425.39, 638.18 and 206.18 is: 309.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    425.39 : 638.18 = 206.18 : x
  2. Step 2: Convert to fraction form
    425.39/638.18 = 206.18/x
  3. Step 3: Cross multiply
    425.39x = 638.18 × 206.18
  4. Step 4: Simplify right side
    425.39x = 131,577.28
  5. Step 5: Solve for x
    x = 131,577.28/425.39
  6. Step 6: Final answer
    x = 309.31

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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.