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Finding the Fourth Proportional to 87.31, 120.54 and 54.60

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Solution

The fourth proportional to 87.31, 120.54 and 54.60 is: 75.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.31 : 120.54 = 54.60 : x
  2. Step 2: Convert to fraction form
    87.31/120.54 = 54.60/x
  3. Step 3: Cross multiply
    87.31x = 120.54 × 54.60
  4. Step 4: Simplify right side
    87.31x = 6,581.21
  5. Step 5: Solve for x
    x = 6,581.21/87.31
  6. Step 6: Final answer
    x = 75.38

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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.