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Finding the Fourth Proportional to 139.70, 208.11 and 135.45

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Solution

The fourth proportional to 139.70, 208.11 and 135.45 is: 201.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.70 : 208.11 = 135.45 : x
  2. Step 2: Convert to fraction form
    139.70/208.11 = 135.45/x
  3. Step 3: Cross multiply
    139.70x = 208.11 × 135.45
  4. Step 4: Simplify right side
    139.70x = 28,188.50
  5. Step 5: Solve for x
    x = 28,188.50/139.70
  6. Step 6: Final answer
    x = 201.78

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.