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Finding the Fourth Proportional to 80.88, 120.60 and 75.72

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Solution

The fourth proportional to 80.88, 120.60 and 75.72 is: 112.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.88 : 120.60 = 75.72 : x
  2. Step 2: Convert to fraction form
    80.88/120.60 = 75.72/x
  3. Step 3: Cross multiply
    80.88x = 120.60 × 75.72
  4. Step 4: Simplify right side
    80.88x = 9,131.83
  5. Step 5: Solve for x
    x = 9,131.83/80.88
  6. Step 6: Final answer
    x = 112.91

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.