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Finding the Fourth Proportional to 83.81, 125.89 and 79.72

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Solution

The fourth proportional to 83.81, 125.89 and 79.72 is: 119.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    83.81 : 125.89 = 79.72 : x
  2. Step 2: Convert to fraction form
    83.81/125.89 = 79.72/x
  3. Step 3: Cross multiply
    83.81x = 125.89 × 79.72
  4. Step 4: Simplify right side
    83.81x = 10,035.44
  5. Step 5: Solve for x
    x = 10,035.44/83.81
  6. Step 6: Final answer
    x = 119.74

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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.