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Finding the Fourth Proportional to 81.50, 112.19 and 72.77

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Solution

The fourth proportional to 81.50, 112.19 and 72.77 is: 100.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.50 : 112.19 = 72.77 : x
  2. Step 2: Convert to fraction form
    81.50/112.19 = 72.77/x
  3. Step 3: Cross multiply
    81.50x = 112.19 × 72.77
  4. Step 4: Simplify right side
    81.50x = 8,163.14
  5. Step 5: Solve for x
    x = 8,163.14/81.50
  6. Step 6: Final answer
    x = 100.17

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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.