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Finding the Fourth Proportional to 80.50, 120.75 and 75.85

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Solution

The fourth proportional to 80.50, 120.75 and 75.85 is: 113.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.50 : 120.75 = 75.85 : x
  2. Step 2: Convert to fraction form
    80.50/120.75 = 75.85/x
  3. Step 3: Cross multiply
    80.50x = 120.75 × 75.85
  4. Step 4: Simplify right side
    80.50x = 9,158.28
  5. Step 5: Solve for x
    x = 9,158.28/80.50
  6. Step 6: Final answer
    x = 113.77

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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.