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Finding the Fourth Proportional to 81.03, 111.79 and 80.69

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Solution

The fourth proportional to 81.03, 111.79 and 80.69 is: 111.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.03 : 111.79 = 80.69 : x
  2. Step 2: Convert to fraction form
    81.03/111.79 = 80.69/x
  3. Step 3: Cross multiply
    81.03x = 111.79 × 80.69
  4. Step 4: Simplify right side
    81.03x = 9,020.34
  5. Step 5: Solve for x
    x = 9,020.34/81.03
  6. Step 6: Final answer
    x = 111.32

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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.