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Finding the Fourth Proportional to 137.72, 206.19 and 103.40

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Solution

The fourth proportional to 137.72, 206.19 and 103.40 is: 154.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    137.72 : 206.19 = 103.40 : x
  2. Step 2: Convert to fraction form
    137.72/206.19 = 103.40/x
  3. Step 3: Cross multiply
    137.72x = 206.19 × 103.40
  4. Step 4: Simplify right side
    137.72x = 21,319.02
  5. Step 5: Solve for x
    x = 21,319.02/137.72
  6. Step 6: Final answer
    x = 154.81

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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.