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Finding the Fourth Proportional to 126.42, 189.17 and 80.79

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Solution

The fourth proportional to 126.42, 189.17 and 80.79 is: 120.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    126.42 : 189.17 = 80.79 : x
  2. Step 2: Convert to fraction form
    126.42/189.17 = 80.79/x
  3. Step 3: Cross multiply
    126.42x = 189.17 × 80.79
  4. Step 4: Simplify right side
    126.42x = 15,283.04
  5. Step 5: Solve for x
    x = 15,283.04/126.42
  6. Step 6: Final answer
    x = 120.89

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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.