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Finding the Fourth Proportional to 137.18, 188.19 and 128.90

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Solution

The fourth proportional to 137.18, 188.19 and 128.90 is: 176.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    137.18 : 188.19 = 128.90 : x
  2. Step 2: Convert to fraction form
    137.18/188.19 = 128.90/x
  3. Step 3: Cross multiply
    137.18x = 188.19 × 128.90
  4. Step 4: Simplify right side
    137.18x = 24,257.05
  5. Step 5: Solve for x
    x = 24,257.05/137.18
  6. Step 6: Final answer
    x = 176.83

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.