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Finding the Fourth Proportional to 126.43, 189.21 and 80.80

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Solution

The fourth proportional to 126.43, 189.21 and 80.80 is: 120.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    126.43 : 189.21 = 80.80 : x
  2. Step 2: Convert to fraction form
    126.43/189.21 = 80.80/x
  3. Step 3: Cross multiply
    126.43x = 189.21 × 80.80
  4. Step 4: Simplify right side
    126.43x = 15,288.17
  5. Step 5: Solve for x
    x = 15,288.17/126.43
  6. Step 6: Final answer
    x = 120.92

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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.