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Finding the Fourth Proportional to 206.49, 309.43 and 137.78

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Solution

The fourth proportional to 206.49, 309.43 and 137.78 is: 206.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    206.49 : 309.43 = 137.78 : x
  2. Step 2: Convert to fraction form
    206.49/309.43 = 137.78/x
  3. Step 3: Cross multiply
    206.49x = 309.43 × 137.78
  4. Step 4: Simplify right side
    206.49x = 42,631.03
  5. Step 5: Solve for x
    x = 42,631.03/206.49
  6. Step 6: Final answer
    x = 206.46

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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.