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Finding the Fourth Proportional to 80.87, 121.30 and 75.80

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Solution

The fourth proportional to 80.87, 121.30 and 75.80 is: 113.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.87 : 121.30 = 75.80 : x
  2. Step 2: Convert to fraction form
    80.87/121.30 = 75.80/x
  3. Step 3: Cross multiply
    80.87x = 121.30 × 75.80
  4. Step 4: Simplify right side
    80.87x = 9,194.65
  5. Step 5: Solve for x
    x = 9,194.65/80.87
  6. Step 6: Final answer
    x = 113.70

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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.