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Finding the Fourth Proportional to 83.72, 124.78 and 80.12

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Solution

The fourth proportional to 83.72, 124.78 and 80.12 is: 119.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    83.72 : 124.78 = 80.12 : x
  2. Step 2: Convert to fraction form
    83.72/124.78 = 80.12/x
  3. Step 3: Cross multiply
    83.72x = 124.78 × 80.12
  4. Step 4: Simplify right side
    83.72x = 9,997.37
  5. Step 5: Solve for x
    x = 9,997.37/83.72
  6. Step 6: Final answer
    x = 119.41

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.