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Finding the Fourth Proportional to 138.50, 208.49 and 98.21

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Solution

The fourth proportional to 138.50, 208.49 and 98.21 is: 147.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.50 : 208.49 = 98.21 : x
  2. Step 2: Convert to fraction form
    138.50/208.49 = 98.21/x
  3. Step 3: Cross multiply
    138.50x = 208.49 × 98.21
  4. Step 4: Simplify right side
    138.50x = 20,474.27
  5. Step 5: Solve for x
    x = 20,474.27/138.50
  6. Step 6: Final answer
    x = 147.83

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.