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Finding the Fourth Proportional to 85.11, 126.89 and 72.34

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Solution

The fourth proportional to 85.11, 126.89 and 72.34 is: 107.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.11 : 126.89 = 72.34 : x
  2. Step 2: Convert to fraction form
    85.11/126.89 = 72.34/x
  3. Step 3: Cross multiply
    85.11x = 126.89 × 72.34
  4. Step 4: Simplify right side
    85.11x = 9,179.22
  5. Step 5: Solve for x
    x = 9,179.22/85.11
  6. Step 6: Final answer
    x = 107.85

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.