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Finding the Fourth Proportional to 154.38, 231.70 and 86.05

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Solution

The fourth proportional to 154.38, 231.70 and 86.05 is: 129.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    154.38 : 231.70 = 86.05 : x
  2. Step 2: Convert to fraction form
    154.38/231.70 = 86.05/x
  3. Step 3: Cross multiply
    154.38x = 231.70 × 86.05
  4. Step 4: Simplify right side
    154.38x = 19,936.63
  5. Step 5: Solve for x
    x = 19,936.63/154.38
  6. Step 6: Final answer
    x = 129.14

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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.