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Finding the Fourth Proportional to 81.53, 112.32 and 72.11

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Solution

The fourth proportional to 81.53, 112.32 and 72.11 is: 99.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.53 : 112.32 = 72.11 : x
  2. Step 2: Convert to fraction form
    81.53/112.32 = 72.11/x
  3. Step 3: Cross multiply
    81.53x = 112.32 × 72.11
  4. Step 4: Simplify right side
    81.53x = 8,099.40
  5. Step 5: Solve for x
    x = 8,099.40/81.53
  6. Step 6: Final answer
    x = 99.34

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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.