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Finding the Fourth Proportional to 139.09, 207.64 and 120.87

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Solution

The fourth proportional to 139.09, 207.64 and 120.87 is: 180.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.09 : 207.64 = 120.87 : x
  2. Step 2: Convert to fraction form
    139.09/207.64 = 120.87/x
  3. Step 3: Cross multiply
    139.09x = 207.64 × 120.87
  4. Step 4: Simplify right side
    139.09x = 25,097.45
  5. Step 5: Solve for x
    x = 25,097.45/139.09
  6. Step 6: Final answer
    x = 180.44

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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.