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Finding the Fourth Proportional to 138.05, 206.94 and 72.99

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Solution

The fourth proportional to 138.05, 206.94 and 72.99 is: 109.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.05 : 206.94 = 72.99 : x
  2. Step 2: Convert to fraction form
    138.05/206.94 = 72.99/x
  3. Step 3: Cross multiply
    138.05x = 206.94 × 72.99
  4. Step 4: Simplify right side
    138.05x = 15,104.55
  5. Step 5: Solve for x
    x = 15,104.55/138.05
  6. Step 6: Final answer
    x = 109.42

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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.