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Finding the Fourth Proportional to 87.32, 130.24 and 85.70

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Solution

The fourth proportional to 87.32, 130.24 and 85.70 is: 127.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.32 : 130.24 = 85.70 : x
  2. Step 2: Convert to fraction form
    87.32/130.24 = 85.70/x
  3. Step 3: Cross multiply
    87.32x = 130.24 × 85.70
  4. Step 4: Simplify right side
    87.32x = 11,161.57
  5. Step 5: Solve for x
    x = 11,161.57/87.32
  6. Step 6: Final answer
    x = 127.82

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.