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Finding the Fourth Proportional to 126.35, 189.56 and 80.72

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Solution

The fourth proportional to 126.35, 189.56 and 80.72 is: 121.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    126.35 : 189.56 = 80.72 : x
  2. Step 2: Convert to fraction form
    126.35/189.56 = 80.72/x
  3. Step 3: Cross multiply
    126.35x = 189.56 × 80.72
  4. Step 4: Simplify right side
    126.35x = 15,301.28
  5. Step 5: Solve for x
    x = 15,301.28/126.35
  6. Step 6: Final answer
    x = 121.10

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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.