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Finding the Fourth Proportional to 81.04, 111.08 and 80.90

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Solution

The fourth proportional to 81.04, 111.08 and 80.90 is: 110.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.04 : 111.08 = 80.90 : x
  2. Step 2: Convert to fraction form
    81.04/111.08 = 80.90/x
  3. Step 3: Cross multiply
    81.04x = 111.08 × 80.90
  4. Step 4: Simplify right side
    81.04x = 8,986.37
  5. Step 5: Solve for x
    x = 8,986.37/81.04
  6. Step 6: Final answer
    x = 110.89

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.