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Finding the Fourth Proportional to 87.85, 131.80 and 55.31

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Solution

The fourth proportional to 87.85, 131.80 and 55.31 is: 82.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.85 : 131.80 = 55.31 : x
  2. Step 2: Convert to fraction form
    87.85/131.80 = 55.31/x
  3. Step 3: Cross multiply
    87.85x = 131.80 × 55.31
  4. Step 4: Simplify right side
    87.85x = 7,289.62
  5. Step 5: Solve for x
    x = 7,289.62/87.85
  6. Step 6: Final answer
    x = 82.98

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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.