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Finding the Fourth Proportional to 87.03, 129.87 and 78.93

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Solution

The fourth proportional to 87.03, 129.87 and 78.93 is: 117.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.03 : 129.87 = 78.93 : x
  2. Step 2: Convert to fraction form
    87.03/129.87 = 78.93/x
  3. Step 3: Cross multiply
    87.03x = 129.87 × 78.93
  4. Step 4: Simplify right side
    87.03x = 10,250.64
  5. Step 5: Solve for x
    x = 10,250.64/87.03
  6. Step 6: Final answer
    x = 117.78

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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.