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Finding the Fourth Proportional to 77.11, 106.18 and 66.17

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Solution

The fourth proportional to 77.11, 106.18 and 66.17 is: 91.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.11 : 106.18 = 66.17 : x
  2. Step 2: Convert to fraction form
    77.11/106.18 = 66.17/x
  3. Step 3: Cross multiply
    77.11x = 106.18 × 66.17
  4. Step 4: Simplify right side
    77.11x = 7,025.93
  5. Step 5: Solve for x
    x = 7,025.93/77.11
  6. Step 6: Final answer
    x = 91.12

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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.