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Finding the Fourth Proportional to 126.33, 189.57 and 87.78

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Solution

The fourth proportional to 126.33, 189.57 and 87.78 is: 131.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    126.33 : 189.57 = 87.78 : x
  2. Step 2: Convert to fraction form
    126.33/189.57 = 87.78/x
  3. Step 3: Cross multiply
    126.33x = 189.57 × 87.78
  4. Step 4: Simplify right side
    126.33x = 16,640.45
  5. Step 5: Solve for x
    x = 16,640.45/126.33
  6. Step 6: Final answer
    x = 131.72

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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.