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Finding the Fourth Proportional to 77.28, 116.07 and 71.81

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Solution

The fourth proportional to 77.28, 116.07 and 71.81 is: 107.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.28 : 116.07 = 71.81 : x
  2. Step 2: Convert to fraction form
    77.28/116.07 = 71.81/x
  3. Step 3: Cross multiply
    77.28x = 116.07 × 71.81
  4. Step 4: Simplify right side
    77.28x = 8,334.57
  5. Step 5: Solve for x
    x = 8,334.57/77.28
  6. Step 6: Final answer
    x = 107.85

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.