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Finding the Fourth Proportional to 139.92, 208.32 and 139.20

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Solution

The fourth proportional to 139.92, 208.32 and 139.20 is: 207.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.92 : 208.32 = 139.20 : x
  2. Step 2: Convert to fraction form
    139.92/208.32 = 139.20/x
  3. Step 3: Cross multiply
    139.92x = 208.32 × 139.20
  4. Step 4: Simplify right side
    139.92x = 28,998.14
  5. Step 5: Solve for x
    x = 28,998.14/139.92
  6. Step 6: Final answer
    x = 207.25

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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.