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Finding the Fourth Proportional to 91.13, 125.21 and 85.12

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Solution

The fourth proportional to 91.13, 125.21 and 85.12 is: 116.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    91.13 : 125.21 = 85.12 : x
  2. Step 2: Convert to fraction form
    91.13/125.21 = 85.12/x
  3. Step 3: Cross multiply
    91.13x = 125.21 × 85.12
  4. Step 4: Simplify right side
    91.13x = 10,657.77
  5. Step 5: Solve for x
    x = 10,657.77/91.13
  6. Step 6: Final answer
    x = 116.96

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.