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Finding the Fourth Proportional to 187.78, 281.15 and 126.79

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Solution

The fourth proportional to 187.78, 281.15 and 126.79 is: 189.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    187.78 : 281.15 = 126.79 : x
  2. Step 2: Convert to fraction form
    187.78/281.15 = 126.79/x
  3. Step 3: Cross multiply
    187.78x = 281.15 × 126.79
  4. Step 4: Simplify right side
    187.78x = 35,645.86
  5. Step 5: Solve for x
    x = 35,645.86/187.78
  6. Step 6: Final answer
    x = 189.83

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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.