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Finding the Fourth Proportional to 138.24, 206.96 and 84.11

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Solution

The fourth proportional to 138.24, 206.96 and 84.11 is: 125.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.24 : 206.96 = 84.11 : x
  2. Step 2: Convert to fraction form
    138.24/206.96 = 84.11/x
  3. Step 3: Cross multiply
    138.24x = 206.96 × 84.11
  4. Step 4: Simplify right side
    138.24x = 17,405.95
  5. Step 5: Solve for x
    x = 17,405.95/138.24
  6. Step 6: Final answer
    x = 125.91

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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.