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Finding the Fourth Proportional to 137.32, 206.17 and 85.80

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Solution

The fourth proportional to 137.32, 206.17 and 85.80 is: 128.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    137.32 : 206.17 = 85.80 : x
  2. Step 2: Convert to fraction form
    137.32/206.17 = 85.80/x
  3. Step 3: Cross multiply
    137.32x = 206.17 × 85.80
  4. Step 4: Simplify right side
    137.32x = 17,689.39
  5. Step 5: Solve for x
    x = 17,689.39/137.32
  6. Step 6: Final answer
    x = 128.82

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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.