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Finding the Fourth Proportional to 139.05, 209.79 and 133.38

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Solution

The fourth proportional to 139.05, 209.79 and 133.38 is: 201.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.05 : 209.79 = 133.38 : x
  2. Step 2: Convert to fraction form
    139.05/209.79 = 133.38/x
  3. Step 3: Cross multiply
    139.05x = 209.79 × 133.38
  4. Step 4: Simplify right side
    139.05x = 27,981.79
  5. Step 5: Solve for x
    x = 27,981.79/139.05
  6. Step 6: Final answer
    x = 201.24

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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.