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Finding the Fourth Proportional to 139.14, 209.54 and 121.32

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Solution

The fourth proportional to 139.14, 209.54 and 121.32 is: 182.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.14 : 209.54 = 121.32 : x
  2. Step 2: Convert to fraction form
    139.14/209.54 = 121.32/x
  3. Step 3: Cross multiply
    139.14x = 209.54 × 121.32
  4. Step 4: Simplify right side
    139.14x = 25,421.70
  5. Step 5: Solve for x
    x = 25,421.70/139.14
  6. Step 6: Final answer
    x = 182.71

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.