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Finding the Fourth Proportional to 81.23, 112.05 and 70.85

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Solution

The fourth proportional to 81.23, 112.05 and 70.85 is: 97.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.23 : 112.05 = 70.85 : x
  2. Step 2: Convert to fraction form
    81.23/112.05 = 70.85/x
  3. Step 3: Cross multiply
    81.23x = 112.05 × 70.85
  4. Step 4: Simplify right side
    81.23x = 7,938.74
  5. Step 5: Solve for x
    x = 7,938.74/81.23
  6. Step 6: Final answer
    x = 97.73

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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.