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Finding the Fourth Proportional to 77.81, 116.72 and 68.75

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Solution

The fourth proportional to 77.81, 116.72 and 68.75 is: 103.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.81 : 116.72 = 68.75 : x
  2. Step 2: Convert to fraction form
    77.81/116.72 = 68.75/x
  3. Step 3: Cross multiply
    77.81x = 116.72 × 68.75
  4. Step 4: Simplify right side
    77.81x = 8,025.31
  5. Step 5: Solve for x
    x = 8,025.31/77.81
  6. Step 6: Final answer
    x = 103.14

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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.