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Finding the Fourth Proportional to 76.68, 105.84 and 66.96

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Solution

The fourth proportional to 76.68, 105.84 and 66.96 is: 92.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.68 : 105.84 = 66.96 : x
  2. Step 2: Convert to fraction form
    76.68/105.84 = 66.96/x
  3. Step 3: Cross multiply
    76.68x = 105.84 × 66.96
  4. Step 4: Simplify right side
    76.68x = 7,087.05
  5. Step 5: Solve for x
    x = 7,087.05/76.68
  6. Step 6: Final answer
    x = 92.42

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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.