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Finding the Fourth Proportional to 87.01, 129.90 and 76.65

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Solution

The fourth proportional to 87.01, 129.90 and 76.65 is: 114.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.01 : 129.90 = 76.65 : x
  2. Step 2: Convert to fraction form
    87.01/129.90 = 76.65/x
  3. Step 3: Cross multiply
    87.01x = 129.90 × 76.65
  4. Step 4: Simplify right side
    87.01x = 9,956.64
  5. Step 5: Solve for x
    x = 9,956.64/87.01
  6. Step 6: Final answer
    x = 114.43

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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.