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Finding the Fourth Proportional to 139.34, 208.17 and 120.74

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Solution

The fourth proportional to 139.34, 208.17 and 120.74 is: 180.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.34 : 208.17 = 120.74 : x
  2. Step 2: Convert to fraction form
    139.34/208.17 = 120.74/x
  3. Step 3: Cross multiply
    139.34x = 208.17 × 120.74
  4. Step 4: Simplify right side
    139.34x = 25,133.84
  5. Step 5: Solve for x
    x = 25,133.84/139.34
  6. Step 6: Final answer
    x = 180.38

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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.