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Finding the Fourth Proportional to 81.27, 112.19 and 72.36

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Solution

The fourth proportional to 81.27, 112.19 and 72.36 is: 99.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.27 : 112.19 = 72.36 : x
  2. Step 2: Convert to fraction form
    81.27/112.19 = 72.36/x
  3. Step 3: Cross multiply
    81.27x = 112.19 × 72.36
  4. Step 4: Simplify right side
    81.27x = 8,117.71
  5. Step 5: Solve for x
    x = 8,117.71/81.27
  6. Step 6: Final answer
    x = 99.89

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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.