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Finding the Fourth Proportional to 63.11, 87.08 and 39.79

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Solution

The fourth proportional to 63.11, 87.08 and 39.79 is: 54.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    63.11 : 87.08 = 39.79 : x
  2. Step 2: Convert to fraction form
    63.11/87.08 = 39.79/x
  3. Step 3: Cross multiply
    63.11x = 87.08 × 39.79
  4. Step 4: Simplify right side
    63.11x = 3,464.82
  5. Step 5: Solve for x
    x = 3,464.82/63.11
  6. Step 6: Final answer
    x = 54.90

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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.