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Finding the Fourth Proportional to 139.98, 208.63 and 138.86

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Solution

The fourth proportional to 139.98, 208.63 and 138.86 is: 206.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.98 : 208.63 = 138.86 : x
  2. Step 2: Convert to fraction form
    139.98/208.63 = 138.86/x
  3. Step 3: Cross multiply
    139.98x = 208.63 × 138.86
  4. Step 4: Simplify right side
    139.98x = 28,969.67
  5. Step 5: Solve for x
    x = 28,969.67/139.98
  6. Step 6: Final answer
    x = 206.96

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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.