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Finding the Fourth Proportional to 87.32, 130.78 and 76

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Solution

The fourth proportional to 87.32, 130.78 and 76 is: 113.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.32 : 130.78 = 76 : x
  2. Step 2: Convert to fraction form
    87.32/130.78 = 76/x
  3. Step 3: Cross multiply
    87.32x = 130.78 × 76
  4. Step 4: Simplify right side
    87.32x = 9,939.28
  5. Step 5: Solve for x
    x = 9,939.28/87.32
  6. Step 6: Final answer
    x = 113.83

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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.