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Finding the Fourth Proportional to 126.58, 189.81 and 77.86

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Solution

The fourth proportional to 126.58, 189.81 and 77.86 is: 116.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    126.58 : 189.81 = 77.86 : x
  2. Step 2: Convert to fraction form
    126.58/189.81 = 77.86/x
  3. Step 3: Cross multiply
    126.58x = 189.81 × 77.86
  4. Step 4: Simplify right side
    126.58x = 14,778.61
  5. Step 5: Solve for x
    x = 14,778.61/126.58
  6. Step 6: Final answer
    x = 116.75

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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.