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Finding the Fourth Proportional to 81.13, 121.47 and 58.18

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Solution

The fourth proportional to 81.13, 121.47 and 58.18 is: 87.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.13 : 121.47 = 58.18 : x
  2. Step 2: Convert to fraction form
    81.13/121.47 = 58.18/x
  3. Step 3: Cross multiply
    81.13x = 121.47 × 58.18
  4. Step 4: Simplify right side
    81.13x = 7,067.12
  5. Step 5: Solve for x
    x = 7,067.12/81.13
  6. Step 6: Final answer
    x = 87.11

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.