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Finding the Fourth Proportional to 137.75, 206.45 and 69.20

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Solution

The fourth proportional to 137.75, 206.45 and 69.20 is: 103.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    137.75 : 206.45 = 69.20 : x
  2. Step 2: Convert to fraction form
    137.75/206.45 = 69.20/x
  3. Step 3: Cross multiply
    137.75x = 206.45 × 69.20
  4. Step 4: Simplify right side
    137.75x = 14,287.16
  5. Step 5: Solve for x
    x = 14,287.16/137.75
  6. Step 6: Final answer
    x = 103.72

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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.