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Finding the Fourth Proportional to 126.42, 189.20 and 80.80

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Solution

The fourth proportional to 126.42, 189.20 and 80.80 is: 120.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    126.42 : 189.20 = 80.80 : x
  2. Step 2: Convert to fraction form
    126.42/189.20 = 80.80/x
  3. Step 3: Cross multiply
    126.42x = 189.20 × 80.80
  4. Step 4: Simplify right side
    126.42x = 15,287.36
  5. Step 5: Solve for x
    x = 15,287.36/126.42
  6. Step 6: Final answer
    x = 120.93

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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.