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Finding the Fourth Proportional to 87.29, 120.47 and 54.57

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Solution

The fourth proportional to 87.29, 120.47 and 54.57 is: 75.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.29 : 120.47 = 54.57 : x
  2. Step 2: Convert to fraction form
    87.29/120.47 = 54.57/x
  3. Step 3: Cross multiply
    87.29x = 120.47 × 54.57
  4. Step 4: Simplify right side
    87.29x = 6,574.05
  5. Step 5: Solve for x
    x = 6,574.05/87.29
  6. Step 6: Final answer
    x = 75.31

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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.