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Finding the Fourth Proportional to 71.72, 98.97 and 38.97

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Solution

The fourth proportional to 71.72, 98.97 and 38.97 is: 53.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.72 : 98.97 = 38.97 : x
  2. Step 2: Convert to fraction form
    71.72/98.97 = 38.97/x
  3. Step 3: Cross multiply
    71.72x = 98.97 × 38.97
  4. Step 4: Simplify right side
    71.72x = 3,856.90
  5. Step 5: Solve for x
    x = 3,856.90/71.72
  6. Step 6: Final answer
    x = 53.78

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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.