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Finding the Fourth Proportional to 87.89, 131.72 and 39.70

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Solution

The fourth proportional to 87.89, 131.72 and 39.70 is: 59.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.89 : 131.72 = 39.70 : x
  2. Step 2: Convert to fraction form
    87.89/131.72 = 39.70/x
  3. Step 3: Cross multiply
    87.89x = 131.72 × 39.70
  4. Step 4: Simplify right side
    87.89x = 5,228.43
  5. Step 5: Solve for x
    x = 5,228.43/87.89
  6. Step 6: Final answer
    x = 59.49

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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.