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Finding the Fourth Proportional to 137.78, 206.40 and 107.20

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Solution

The fourth proportional to 137.78, 206.40 and 107.20 is: 160.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    137.78 : 206.40 = 107.20 : x
  2. Step 2: Convert to fraction form
    137.78/206.40 = 107.20/x
  3. Step 3: Cross multiply
    137.78x = 206.40 × 107.20
  4. Step 4: Simplify right side
    137.78x = 22,126.08
  5. Step 5: Solve for x
    x = 22,126.08/137.78
  6. Step 6: Final answer
    x = 160.59

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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.