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Finding the Fourth Proportional to 87.39, 120.61 and 55.46

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Solution

The fourth proportional to 87.39, 120.61 and 55.46 is: 76.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.39 : 120.61 = 55.46 : x
  2. Step 2: Convert to fraction form
    87.39/120.61 = 55.46/x
  3. Step 3: Cross multiply
    87.39x = 120.61 × 55.46
  4. Step 4: Simplify right side
    87.39x = 6,689.40
  5. Step 5: Solve for x
    x = 6,689.40/87.39
  6. Step 6: Final answer
    x = 76.55

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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.