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Finding the Fourth Proportional to 87.34, 120.39 and 71.75

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Solution

The fourth proportional to 87.34, 120.39 and 71.75 is: 98.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.34 : 120.39 = 71.75 : x
  2. Step 2: Convert to fraction form
    87.34/120.39 = 71.75/x
  3. Step 3: Cross multiply
    87.34x = 120.39 × 71.75
  4. Step 4: Simplify right side
    87.34x = 8,637.98
  5. Step 5: Solve for x
    x = 8,637.98/87.34
  6. Step 6: Final answer
    x = 98.91

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.