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Finding the Fourth Proportional to 51.72, 71.31 and 39.97

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Solution

The fourth proportional to 51.72, 71.31 and 39.97 is: 55.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    51.72 : 71.31 = 39.97 : x
  2. Step 2: Convert to fraction form
    51.72/71.31 = 39.97/x
  3. Step 3: Cross multiply
    51.72x = 71.31 × 39.97
  4. Step 4: Simplify right side
    51.72x = 2,850.26
  5. Step 5: Solve for x
    x = 2,850.26/51.72
  6. Step 6: Final answer
    x = 55.11

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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.