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Finding the Fourth Proportional to 77.09, 105.86 and 68.87

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Solution

The fourth proportional to 77.09, 105.86 and 68.87 is: 94.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.09 : 105.86 = 68.87 : x
  2. Step 2: Convert to fraction form
    77.09/105.86 = 68.87/x
  3. Step 3: Cross multiply
    77.09x = 105.86 × 68.87
  4. Step 4: Simplify right side
    77.09x = 7,291.02
  5. Step 5: Solve for x
    x = 7,291.02/77.09
  6. Step 6: Final answer
    x = 94.58

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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.