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Finding the Fourth Proportional to 87.70, 131.47 and 56.77

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Solution

The fourth proportional to 87.70, 131.47 and 56.77 is: 85.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.70 : 131.47 = 56.77 : x
  2. Step 2: Convert to fraction form
    87.70/131.47 = 56.77/x
  3. Step 3: Cross multiply
    87.70x = 131.47 × 56.77
  4. Step 4: Simplify right side
    87.70x = 7,462.61
  5. Step 5: Solve for x
    x = 7,462.61/87.70
  6. Step 6: Final answer
    x = 85.10

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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.