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Finding the Fourth Proportional to 138.58, 207.81 and 47.25

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Solution

The fourth proportional to 138.58, 207.81 and 47.25 is: 70.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.58 : 207.81 = 47.25 : x
  2. Step 2: Convert to fraction form
    138.58/207.81 = 47.25/x
  3. Step 3: Cross multiply
    138.58x = 207.81 × 47.25
  4. Step 4: Simplify right side
    138.58x = 9,817.98
  5. Step 5: Solve for x
    x = 9,817.98/138.58
  6. Step 6: Final answer
    x = 70.85

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.