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Finding the Fourth Proportional to 87.21, 120.35 and 47.87

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Solution

The fourth proportional to 87.21, 120.35 and 47.87 is: 66.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.21 : 120.35 = 47.87 : x
  2. Step 2: Convert to fraction form
    87.21/120.35 = 47.87/x
  3. Step 3: Cross multiply
    87.21x = 120.35 × 47.87
  4. Step 4: Simplify right side
    87.21x = 5,761.07
  5. Step 5: Solve for x
    x = 5,761.07/87.21
  6. Step 6: Final answer
    x = 66.06

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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.