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Finding the Fourth Proportional to 139.90, 210.66 and 122.08

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Solution

The fourth proportional to 139.90, 210.66 and 122.08 is: 183.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    139.90 : 210.66 = 122.08 : x
  2. Step 2: Convert to fraction form
    139.90/210.66 = 122.08/x
  3. Step 3: Cross multiply
    139.90x = 210.66 × 122.08
  4. Step 4: Simplify right side
    139.90x = 25,717.37
  5. Step 5: Solve for x
    x = 25,717.37/139.90
  6. Step 6: Final answer
    x = 183.83

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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.