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Finding the Fourth Proportional to 63.28, 87.31 and 39.97

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Solution

The fourth proportional to 63.28, 87.31 and 39.97 is: 55.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    63.28 : 87.31 = 39.97 : x
  2. Step 2: Convert to fraction form
    63.28/87.31 = 39.97/x
  3. Step 3: Cross multiply
    63.28x = 87.31 × 39.97
  4. Step 4: Simplify right side
    63.28x = 3,489.46
  5. Step 5: Solve for x
    x = 3,489.46/63.28
  6. Step 6: Final answer
    x = 55.15

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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.