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Finding the Fourth Proportional to 126.05, 189.09 and 71.90

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Solution

The fourth proportional to 126.05, 189.09 and 71.90 is: 107.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    126.05 : 189.09 = 71.90 : x
  2. Step 2: Convert to fraction form
    126.05/189.09 = 71.90/x
  3. Step 3: Cross multiply
    126.05x = 189.09 × 71.90
  4. Step 4: Simplify right side
    126.05x = 13,595.57
  5. Step 5: Solve for x
    x = 13,595.57/126.05
  6. Step 6: Final answer
    x = 107.86

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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.