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Finding the Fourth Proportional to 81.00, 120.91 and 71.27

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Solution

The fourth proportional to 81.00, 120.91 and 71.27 is: 106.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.00 : 120.91 = 71.27 : x
  2. Step 2: Convert to fraction form
    81.00/120.91 = 71.27/x
  3. Step 3: Cross multiply
    81.00x = 120.91 × 71.27
  4. Step 4: Simplify right side
    81.00x = 8,616.78
  5. Step 5: Solve for x
    x = 8,616.78/81.00
  6. Step 6: Final answer
    x = 106.38

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.