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Finding the Fourth Proportional to 80.98, 121.39 and 56.86

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Solution

The fourth proportional to 80.98, 121.39 and 56.86 is: 85.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.98 : 121.39 = 56.86 : x
  2. Step 2: Convert to fraction form
    80.98/121.39 = 56.86/x
  3. Step 3: Cross multiply
    80.98x = 121.39 × 56.86
  4. Step 4: Simplify right side
    80.98x = 6,902.24
  5. Step 5: Solve for x
    x = 6,902.24/80.98
  6. Step 6: Final answer
    x = 85.23

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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.