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Finding the Fourth Proportional to 126.68, 189.85 and 81.01

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Solution

The fourth proportional to 126.68, 189.85 and 81.01 is: 121.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    126.68 : 189.85 = 81.01 : x
  2. Step 2: Convert to fraction form
    126.68/189.85 = 81.01/x
  3. Step 3: Cross multiply
    126.68x = 189.85 × 81.01
  4. Step 4: Simplify right side
    126.68x = 15,379.75
  5. Step 5: Solve for x
    x = 15,379.75/126.68
  6. Step 6: Final answer
    x = 121.41

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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.