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Finding the Fourth Proportional to 126.78, 190.19 and 72.61

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Solution

The fourth proportional to 126.78, 190.19 and 72.61 is: 108.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    126.78 : 190.19 = 72.61 : x
  2. Step 2: Convert to fraction form
    126.78/190.19 = 72.61/x
  3. Step 3: Cross multiply
    126.78x = 190.19 × 72.61
  4. Step 4: Simplify right side
    126.78x = 13,809.70
  5. Step 5: Solve for x
    x = 13,809.70/126.78
  6. Step 6: Final answer
    x = 108.93

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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.