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Finding the Fourth Proportional to 77.05, 105.64 and 75.69

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Solution

The fourth proportional to 77.05, 105.64 and 75.69 is: 103.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.05 : 105.64 = 75.69 : x
  2. Step 2: Convert to fraction form
    77.05/105.64 = 75.69/x
  3. Step 3: Cross multiply
    77.05x = 105.64 × 75.69
  4. Step 4: Simplify right side
    77.05x = 7,995.89
  5. Step 5: Solve for x
    x = 7,995.89/77.05
  6. Step 6: Final answer
    x = 103.78

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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.