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Finding the Fourth Proportional to 154.38, 231.17 and 85.80

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Solution

The fourth proportional to 154.38, 231.17 and 85.80 is: 128.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    154.38 : 231.17 = 85.80 : x
  2. Step 2: Convert to fraction form
    154.38/231.17 = 85.80/x
  3. Step 3: Cross multiply
    154.38x = 231.17 × 85.80
  4. Step 4: Simplify right side
    154.38x = 19,833.96
  5. Step 5: Solve for x
    x = 19,833.96/154.38
  6. Step 6: Final answer
    x = 128.47

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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.