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Finding the Fourth Proportional to 76.82, 106.21 and 69.91

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Solution

The fourth proportional to 76.82, 106.21 and 69.91 is: 96.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.82 : 106.21 = 69.91 : x
  2. Step 2: Convert to fraction form
    76.82/106.21 = 69.91/x
  3. Step 3: Cross multiply
    76.82x = 106.21 × 69.91
  4. Step 4: Simplify right side
    76.82x = 7,425.56
  5. Step 5: Solve for x
    x = 7,425.56/76.82
  6. Step 6: Final answer
    x = 96.67

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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.