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Finding the Fourth Proportional to 91.20, 125.87 and 66.63

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Solution

The fourth proportional to 91.20, 125.87 and 66.63 is: 91.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    91.20 : 125.87 = 66.63 : x
  2. Step 2: Convert to fraction form
    91.20/125.87 = 66.63/x
  3. Step 3: Cross multiply
    91.20x = 125.87 × 66.63
  4. Step 4: Simplify right side
    91.20x = 8,386.72
  5. Step 5: Solve for x
    x = 8,386.72/91.20
  6. Step 6: Final answer
    x = 91.96

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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.