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Finding the Fourth Proportional to 81.48, 111.64 and 80.47

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Solution

The fourth proportional to 81.48, 111.64 and 80.47 is: 110.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.48 : 111.64 = 80.47 : x
  2. Step 2: Convert to fraction form
    81.48/111.64 = 80.47/x
  3. Step 3: Cross multiply
    81.48x = 111.64 × 80.47
  4. Step 4: Simplify right side
    81.48x = 8,983.19
  5. Step 5: Solve for x
    x = 8,983.19/81.48
  6. Step 6: Final answer
    x = 110.25

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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.