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Finding the Fourth Proportional to 206.94, 309.91 and 138.40

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Solution

The fourth proportional to 206.94, 309.91 and 138.40 is: 207.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    206.94 : 309.91 = 138.40 : x
  2. Step 2: Convert to fraction form
    206.94/309.91 = 138.40/x
  3. Step 3: Cross multiply
    206.94x = 309.91 × 138.40
  4. Step 4: Simplify right side
    206.94x = 42,891.54
  5. Step 5: Solve for x
    x = 42,891.54/206.94
  6. Step 6: Final answer
    x = 207.27

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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.