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Finding the Fourth Proportional to 79.81, 119.82 and 67.86

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Solution

The fourth proportional to 79.81, 119.82 and 67.86 is: 101.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.81 : 119.82 = 67.86 : x
  2. Step 2: Convert to fraction form
    79.81/119.82 = 67.86/x
  3. Step 3: Cross multiply
    79.81x = 119.82 × 67.86
  4. Step 4: Simplify right side
    79.81x = 8,130.80
  5. Step 5: Solve for x
    x = 8,130.80/79.81
  6. Step 6: Final answer
    x = 101.88

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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.