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Finding the Fourth Proportional to 142.59, 213.84 and 80.85

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Solution

The fourth proportional to 142.59, 213.84 and 80.85 is: 121.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    142.59 : 213.84 = 80.85 : x
  2. Step 2: Convert to fraction form
    142.59/213.84 = 80.85/x
  3. Step 3: Cross multiply
    142.59x = 213.84 × 80.85
  4. Step 4: Simplify right side
    142.59x = 17,288.96
  5. Step 5: Solve for x
    x = 17,288.96/142.59
  6. Step 6: Final answer
    x = 121.25

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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.