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Finding the Fourth Proportional to 87.70, 130.52 and 86.80

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Solution

The fourth proportional to 87.70, 130.52 and 86.80 is: 129.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.70 : 130.52 = 86.80 : x
  2. Step 2: Convert to fraction form
    87.70/130.52 = 86.80/x
  3. Step 3: Cross multiply
    87.70x = 130.52 × 86.80
  4. Step 4: Simplify right side
    87.70x = 11,329.14
  5. Step 5: Solve for x
    x = 11,329.14/87.70
  6. Step 6: Final answer
    x = 129.18

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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.