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Finding the Fourth Proportional to 81.17, 111.98 and 53.49

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Solution

The fourth proportional to 81.17, 111.98 and 53.49 is: 73.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.17 : 111.98 = 53.49 : x
  2. Step 2: Convert to fraction form
    81.17/111.98 = 53.49/x
  3. Step 3: Cross multiply
    81.17x = 111.98 × 53.49
  4. Step 4: Simplify right side
    81.17x = 5,989.79
  5. Step 5: Solve for x
    x = 5,989.79/81.17
  6. Step 6: Final answer
    x = 73.79

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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.